Leached diamond elements and leaching systems, methods and assemblies for processing diamond elements

ABSTRACT

Method of processing a polycrystalline diamond element may include laser ablating at least a portion of a polycrystalline diamond element to form a laser-shaped surface and exposing at least a portion of the laser-shaped surface to a leaching solution to define a leached polycrystalline diamond volume and an unleached polycrystalline diamond volume.

This application is a continuation of U.S. patent application Ser. No.17/061,419, filed Oct. 1, 2020, for “LEACHED SUPERABRASIVE ELEMENTS ANDLEACHING SYSTEMS, METHODS AND ASSEMBLIES FOR PROCESSING SUPERABRASIVEELEMENTS,” which application is a divisional of U.S. patent applicationSer. No. 14/178,251, filed Feb. 11, 2014, for “LEACHED SUPERABRASIVEELEMENTS AND LEACHING SYSTEMS, METHODS AND ASSEMBLIES FOR PROCESSINGSUPERABRASIVE ELEMENTS,” the disclosure of which is hereby incorporatedherein in its entirety by this reference.

BACKGROUND

Wear-resistant, superabrasive materials are traditionally utilized for avariety of mechanical applications. For example, polycrystalline diamond(“PCD”) materials are often used in drilling tools (e.g., cuttingelements, gage trimmers, etc.), machining equipment, bearingapparatuses, wire-drawing machinery, and in other mechanical systems.Conventional superabrasive materials have found utility as superabrasivecutting elements in rotary drill bits, such as roller cone drill bitsand fixed-cutter drill bits. A conventional cutting element may includea superabrasive layer or table, such as a PCD table. The cutting elementmay be brazed, press-fit, or otherwise secured into a preformed pocket,socket, or other receptacle formed in the rotary drill bit. In anotherconfiguration, the substrate may be brazed or otherwise joined to anattachment member such as a stud or a cylindrical backing. Generally, arotary drill bit may include one or more PCD cutting elements affixed toa bit body of the rotary drill bit.

As mentioned above, conventional superabrasive materials have foundutility as bearing elements, which may include bearing elements utilizedin thrust bearing and radial bearing apparatuses. A conventional bearingelement typically includes a superabrasive layer or table, such as a PCDtable, bonded to a substrate. One or more bearing elements may bemounted to a bearing rotor or stator by press-fitting, brazing, orthrough other suitable methods of attachment. Typically, bearingelements mounted to a bearing rotor have superabrasive faces configuredto contact corresponding superabrasive faces of bearing elements mountedto an adjacent bearing stator.

Cutting elements having a PCD table may be formed and bonded to asubstrate using an ultra-high pressure, ultra-high temperature (“HPHT”)sintering process. Often, cutting elements having a PCD table arefabricated by placing a cemented carbide substrate, such as acobalt-cemented tungsten carbide substrate, into a container orcartridge with a volume of diamond particles positioned on a surface ofthe cemented carbide substrate. A number of such cartridges may beloaded into a HPHT press. The substrates and diamond particle volumesmay then be processed under HPHT conditions in the presence of acatalyst material that causes the diamond particles to bond to oneanother to form a diamond table having a matrix of bonded diamondcrystals. The catalyst material is often a metal-solvent catalyst, suchas cobalt, nickel, and/or iron, that facilitates intergrowth and bondingof the diamond crystals.

In one conventional approach, a constituent of the cemented-carbidesubstrate, such as cobalt from a cobalt-cemented tungsten carbidesubstrate, liquefies and sweeps from a region adjacent to the volume ofdiamond particles into interstitial regions between the diamondparticles during the HPHT process. The cobalt may act as a catalyst tofacilitate the formation of bonded diamond crystals. A metal-solventcatalyst may also be mixed with a volume of diamond particles prior tosubjecting the diamond particles and substrate to the HPHT process.

The metal-solvent catalyst may dissolve carbon from the diamondparticles and portions of the diamond particles that graphitize due tothe high temperatures used in the HPHT process. The solubility of thestable diamond phase in the metal-solvent catalyst may be lower thanthat of the metastable graphite phase under HPHT conditions. As a resultof the solubility difference, the graphite tends to dissolve into themetal-solvent catalyst and the diamond tends to deposit onto existingdiamond particles to form diamond-to-diamond bonds. Accordingly, diamondgrains may become mutually bonded to form a matrix of polycrystallinediamond, with interstitial regions defined between the bonded diamondgrains being occupied by the metal-solvent catalyst. In addition todissolving carbon and graphite, the metal-solvent catalyst may alsocarry tungsten, tungsten carbide, and/or other materials from thesubstrate into the PCD layer of the cutting element.

The presence of the metal-solvent catalyst and/or other materials in thediamond table may reduce the thermal stability of the diamond table atelevated temperatures. For example, the difference in thermal expansioncoefficient between the diamond grains and the solvent catalyst isbelieved to lead to chipping or cracking in the PCD table of a cuttingelement during drilling or cutting operations. The chipping or crackingin the PCD table may degrade the mechanical properties of the cuttingelement or lead to failure of the cutting element. Additionally, at hightemperatures, diamond grains may undergo a chemical breakdown orback-conversion with the metal-solvent catalyst. Further, portions ofdiamond grains may transform to carbon monoxide, carbon dioxide,graphite, or combinations thereof, thereby degrading the mechanicalproperties of the PCD material.

Accordingly, it is desirable to remove a metal-solvent catalyst from aPCD material in situations where the PCD material may be exposed to hightemperatures. Chemical leaching is often used to dissolve and removevarious materials from the PCD layer. For example, chemical leaching maybe used to remove metal-solvent catalysts, such as cobalt, from regionsof a PCD layer that may experience elevated temperatures duringdrilling, such as regions adjacent to the working surfaces of the PCDlayer.

During conventional leaching of a PCD table, exposed surface regions ofthe PCD table are immersed in a leaching solution until interstitialcomponents, such as a metal-solvent catalyst, are removed to a desireddepth from the exposed surface regions. Following leaching, aninterface, or leach boundary, between a leached portion and an unleachedportion of the PCD table is often oriented in a direction that isparallel to a surface of the PCD table. For example, the leach boundaryof a PCD cutting element may be disposed a selected distance away from awear region (e.g., cutting edge, cutting face, side surface) of acutting element such that, when the cutting element is mounted to adrill bit, the leach boundary is not continuously forced against amaterial, such as a rock formation, during drilling. However, as the PCDtable of the cutting element is worn down through use over time, a wearregion of the PCD table may eventually intersect the leach boundary,resulting in undesired spalling, cracking, and/or thermal damage at ornear the leach boundary during drilling. Such damage to the PCD tablemay reduce the effectiveness and usable life of the PCD cutting element.

SUMMARY

The instant disclosure is directed to exemplary leached superabrasiveelements and leaching systems, methods, and assemblies for processingsuperabrasive elements. According to at least one embodiment, apolycrystalline diamond element may comprise a polycrystalline diamondtable having a body of bonded diamond particles with interstitialregions, a first volume of the body comprising an interstitial materialwithin the interstitial regions and a second volume of the body having alower concentration of interstitial material within the interstitialregions than the first volume. The polycrystalline diamond element mayalso have an element face and a peripheral surface extending around anouter periphery of the element face. The first volume may be locatedadjacent to a central portion of the element face and the second volumemay be located adjacent to the peripheral surface.

According to at least one embodiment, a boundary region between thefirst volume and the second volume may extend from the peripheralsurface to the element face. The polycrystalline diamond element mayalso comprise a chamfer extending between the element face and theperipheral surface. The second volume may be adjacent to the chamfer. Insome embodiments, the polycrystalline diamond element may be centeredabout a central axis and a percentage ratio of a diameter of the centralportion of the element face defined by the first volume to a diameter ofan intersection of the element face and the chamfer, relative to thecentral axis, may be greater than about 10%. The depth, in a directionperpendicular to the chamfer, of the second volume from the chamfer maybe greater than a depth, in a direction perpendicular to the elementface, of the second volume from the element face. In at least oneembodiment, a boundary region between the first volume and the secondvolume may extend from about an intersection of the peripheral surfaceand the chamfer to about an intersection of the element face and thechamfer.

According to various embodiments, a percentage ratio of a diameter ofthe central portion of the element face defined by the first volume to adiameter of the peripheral surface of the polycrystalline diamondelement, relative to a central axis, may be greater than about 10%. Thepercentage ratio of the diameter of the central portion of the elementface defined by the first volume to the diameter of the peripheralsurface of the polycrystalline diamond element, relative to the centralaxis, may be between about 15% to about 40%. In some embodiments, thepercentage ratio of the diameter of the central portion of the elementface defined by the first volume to the diameter of the peripheralsurface of the polycrystalline diamond element, relative to the centralaxis, may be between about 20% to about 35%.

According to at least one embodiment, the first volume may define aconcave region at a boundary region between the first volume and thesecond volume. The central portion of the element face may be defined bythe first volume and an outer portion of the element face surroundingthe central portion of the element face may be defined by the secondvolume. The element face may be substantially defined by the firstvolume. The polycrystalline diamond element may also comprise asubstrate adjacent to a side of the polycrystalline diamond tabledisposed apart from the element face.

According to at least one embodiment, a method of processing apolycrystalline diamond element may comprise forming a concave region ina polycrystalline diamond element, exposing at least a portion of theconcave region to a leaching solution, and removing at least a portionof the polycrystalline diamond material that was exposed to the leachingsolution from the polycrystalline diamond element. In variousembodiments, following removing the polycrystalline diamond materialfrom at least the portion of the polycrystalline diamond element, thepolycrystalline diamond element may comprise an element face, aperipheral surface extending around an outer periphery of the elementface, and a chamfer extending between the element face and theperipheral surface.

In some embodiments, exposing the region of the polycrystalline diamondelement to the leaching solution may comprise removing an interstitialmaterial from a first volume of the polycrystalline diamond element to afirst depth. Removing the polycrystalline diamond material from at leastthe portion of the polycrystalline diamond element may further compriseremoving the polycrystalline diamond material to a second depthapproximately equal to or greater than the first depth.

In additional embodiments, a method of processing a polycrystallinediamond element may comprise forming a masking layer over at least aportion of a polycrystalline diamond element, and exposing thepolycrystalline diamond element to a leaching solution such that theleaching solution contacts at least a portion of the masking layer. Themasking layer may be formed over at least a central portion of theelement face.

In some embodiments, the masking layer may be formed over a substantialportion of the element face. The masking layer may be substantiallyimpermeable to the leaching solution. In at least one embodiment, themasking layer may comprise a first masking portion and the method mayfurther comprise forming a second masking portion formed over a separateportion of the polycrystalline diamond element than the first maskingportion. The second masking portion may be at least partially soluble inthe leaching solution. According to certain embodiments, exposing thepolycrystalline diamond element to the leaching solution may furthercomprise exposing the second masking portion to the leaching solutionfor a time sufficient to degrade at least a portion of the secondmasking portion such that the leaching solution contacts part of thepolycrystalline diamond element previously covered by the second maskingportion. The masking layer may degrade in the leaching solution.

Features from any of the disclosed embodiments may be used incombination with one another in accordance with the general principlesdescribed herein. These and other embodiments, features, and advantageswill be more fully understood upon reading the following detaileddescription in conjunction with the accompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate a number of exemplary embodimentsand are a part of the specification. Together with the followingdescription, these drawings demonstrate and explain various principlesof the instant disclosure.

FIG. 1 is a perspective view of an exemplary superabrasive elementaccording to at least one embodiment.

FIG. 2 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 3 is a perspective view of an exemplary superabrasive elementaccording to at least one embodiment.

FIG. 4 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 5 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 6 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 7 is a perspective view of an exemplary superabrasive elementaccording to at least one embodiment.

FIG. 8 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 9A is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 9B is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 10 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 11 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 12A is a perspective view of an exemplary superabrasive elementaccording to at least one embodiment.

FIG. 12B is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 13A is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 13B is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 14A is a perspective view of an exemplary superabrasive elementaccording to at least one embodiment.

FIG. 14B is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 14C is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 14D is a cross-sectional side view of a portion of an exemplarysuperabrasive element according to at least one embodiment.

FIG. 14E is a cross-sectional side view of a portion of an exemplarysuperabrasive element according to at least one embodiment.

FIG. 14F is a cross-sectional side view of a portion of an exemplarysuperabrasive element according to at least one embodiment.

FIG. 15A is a perspective view of an exemplary superabrasive elementcoated with a masking layer according to at least one embodiment.

FIG. 15B is a cross-sectional side view of an exemplary superabrasiveelement coated with a masking layer according to at least oneembodiment.

FIG. 15C is a cross-sectional side view of an exemplary superabrasiveelement coated with a masking layer according to at least oneembodiment.

FIG. 15D is a cross-sectional side view of an exemplary superabrasiveelement coated with a masking layer according to at least oneembodiment.

FIG. 16 is a cross-sectional side view of an exemplary superabrasiveelement coated with a masking layer according to at least oneembodiment.

FIG. 17 is a cross-sectional side view of an exemplary superabrasiveelement coated with masking layers according to at least one embodiment.

FIG. 18 is a cross-sectional side view of an exemplary superabrasiveelement positioned within a leaching cup according to at least oneembodiment.

FIG. 19 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 20 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 21 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 22 is a cross-sectional side view of an exemplary superabrasiveelement coated with a masking layer according to at least oneembodiment.

FIG. 23A is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 23B is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 24 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 25 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 26A is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 26B is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 27A is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 27B is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 28 is a cross-sectional side view of an exemplary superabrasiveelement contacting a formation during drilling according to at least oneembodiment.

FIG. 29 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 30 is a cross-sectional side view of an exemplary superabrasiveelement contacting a formation during drilling according to at least oneembodiment.

FIG. 31 is a cross-sectional side view of an exemplary superabrasiveelement according to at least one embodiment.

FIG. 32 is a perspective view of an exemplary drill bit according to atleast one embodiment.

FIG. 33 is a partial cut-away perspective view of an exemplary thrustbearing apparatus according to at least one embodiment.

FIG. 34 is a partial cut-away perspective view of an exemplary radialbearing apparatus according to at least one embodiment.

FIG. 35 is a partial cut-away perspective view of an exemplarysubterranean drilling system according to at least one embodiment.

FIG. 36 is a flow diagram of an exemplary method of processing apolycrystalline diamond element according to at least one embodiment.

FIG. 37 is a flow diagram of an exemplary method of processing apolycrystalline diamond element according to at least one embodiment.

Throughout the drawings, identical reference characters and descriptionsindicate similar, but not necessarily identical, elements. While theexemplary embodiments described herein are susceptible to variousmodifications and alternative forms, specific embodiments have beenshown by way of example in the drawings and will be described in detailherein. However, the exemplary embodiments described herein are notintended to be limited to the particular forms disclosed. Rather, theinstant disclosure covers all modifications, equivalents, andalternatives falling within the scope of the appended claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The instant disclosure is directed to exemplary leached superabrasiveelements and leaching systems, methods, and assemblies for processingsuperabrasive elements. Such superabrasive elements may be used ascutting elements for use in a variety of applications, such as drillingtools, machining equipment, cutting tools, and other apparatuses,without limitation. Superabrasive elements, as disclosed herein, mayalso be used as bearing elements in a variety of bearing applications,such as thrust bearings, radial bearings, and other bearing apparatuses,without limitation.

The terms “superabrasive” and “superhard,” as used herein, may refer toany material having a hardness that is at least equal to a hardness oftungsten carbide. For example, a superabrasive article may represent anarticle of manufacture, at least a portion of which may exhibit ahardness that is equal to or greater than the hardness of tungstencarbide. The term “cutting,” as used herein, may refer to machiningprocesses, drilling processes, boring processes, and/or any othermaterial removal process utilizing a cutting element and/or othercutting apparatus, without limitation.

FIGS. 1 and 2 illustrate an exemplary superabrasive element 10 accordingto at least one embodiment. As illustrated in FIGS. 1 and 2 ,superabrasive element 10 may comprise a superabrasive table 14 affixedto or formed upon a substrate 12. Superabrasive table 14 may be affixedto substrate 12 at interface 26, which may be a planar or nonplanarinterface. Superabrasive element 10 may comprise a rear surface 18, asuperabrasive face 20, and a peripheral surface 15. In some embodiments,peripheral surface 15 may include a substrate side surface 16 formed bysubstrate 12 and a superabrasive side surface 22 formed by superabrasivetable 14. Rear surface 18 may be formed by substrate 12.

Superabrasive element 10 may also comprise a chamfer 24 (i.e., sloped orangled) formed by superabrasive table 14. Chamfer 24 may comprise anangular and/or rounded edge formed at the intersection of superabrasiveside surface 22 and superabrasive face 20. Any other suitable surfaceshape may also be formed at the intersection of superabrasive sidesurface 22 and superabrasive face 20, including, without limitation, anarcuate surface (e.g., a radius, an ovoid shape, or any other roundedshape), a sharp edge, multiple chamfers/radii, a honed edge, and/orcombinations of the foregoing. At least one edge may be formed at theintersection of chamfer 24 and superabrasive face 20 and/or at theintersection of chamfer 24 and superabrasive side surface 22. Forexample, cutting element 10 may comprise one or more cutting edges, suchas an edge 30 and/or or an edge 31. Edge 30 and/or edge 31 may be formedadjacent to chamfer 24 and may be configured to be exposed to and/or incontact with a mining formation during drilling.

In some embodiments, superabrasive element 10 may be utilized as acutting element for a drill bit, in which chamfer 24 acts as a cuttingedge. The phrase “cutting edge” may refer, without limitation, to aportion of a cutting element that is configured to be exposed to and/orin contact with a subterranean formation during drilling. In at leastone embodiment, superabrasive element 10 may be utilized as a bearingelement (e.g., with superabrasive face 20 acting as a bearing surface)configured to contact oppositely facing bearing elements.

According to various embodiments, superabrasive element 10 may alsocomprise a substrate chamfer formed by substrate 12. For example, achamfer comprising an angular and/or rounded edge may be formed bysubstrate 12 at the intersection of substrate side surface 16 and rearsurface 18. Any other suitable surface shape may also be formed at theintersection of substrate side surface 16 and rear surface 18,including, without limitation, an arcuate surface (e.g., a radius, anovoid shape, or any other rounded shape), a sharp edge, multiplechamfers/radii, a honed edge, and/or combinations of the foregoing.

Superabrasive element 10 may comprise any suitable size, shape, and/orgeometry, without limitation. According to at least one embodiment, atleast a portion of superabrasive element 10 may have a substantiallycylindrical shape. For example, superabrasive element 10 may comprise asubstantially cylindrical outer surface surrounding a central axis 28 ofsuperabrasive element 10, as illustrated in FIGS. 1 and 2 . Substrateside surface 16 and superabrasive side surface 22 may, for example, besubstantially cylindrical and may have any suitable diameters relativeto central axis 28, without limitation. According to variousembodiments, substrate side surface 16 and superabrasive side surface 22may have substantially the same outer diameter relative to central axis28.

Substrate 12 may comprise any suitable material on which superabrasivetable 14 may be formed. In at least one embodiment, substrate 12 maycomprise a cemented carbide material, such as a cobalt-cemented tungstencarbide material and/or any other suitable material. In someembodiments, substrate 12 may include a suitable metal-solvent catalystmaterial, such as, for example, cobalt, nickel, iron, and/or alloysthereof. Substrate 12 may also include any suitable material including,without limitation, cemented carbides such as titanium carbide, niobiumcarbide, tantalum carbide, vanadium carbide, chromium carbide, and/orcombinations of any of the preceding carbides cemented with iron,nickel, cobalt, and/or alloys thereof. Superabrasive table 14 may beformed of any suitable superabrasive and/or superhard material orcombination of materials, including, for example PCD. According toadditional embodiments, superabrasive table 14 may comprise cubic boronnitride, silicon carbide, polycrystalline diamond, and/or mixtures orcomposites including one or more of the foregoing materials, withoutlimitation.

Superabrasive table 14 may be formed using any suitable technique.According to some embodiments, superabrasive table 14 may comprise a PCDtable fabricated by subjecting a plurality of diamond particles to anHPHT sintering process in the presence of a metal-solvent catalyst(e.g., cobalt, nickel, iron, or alloys thereof) to facilitateintergrowth between the diamond particles and form a PCD body comprisedof bonded diamond grains that exhibit diamond-to-diamond bondingtherebetween. For example, the metal-solvent catalyst may be mixed withthe diamond particles, infiltrated from a metal-solvent catalyst foil orpowder adjacent to the diamond particles, infiltrated from ametal-solvent catalyst present in a cemented carbide substrate, orcombinations of the foregoing. The bonded diamond grains (e.g.,sp³-bonded diamond grains), so-formed by HPHT sintering the diamondparticles, define interstitial regions with the metal-solvent catalystdisposed within the interstitial regions of the as-sintered PCD body.The diamond particles may exhibit a selected diamond particle sizedistribution. Polycrystalline diamond elements, such as those disclosedin U.S. Pat. Nos. 7,866,418 and 8,297,382, the disclosure of each ofwhich is incorporated herein, in its entirety, by this reference, mayhave magnetic properties in at least some regions as disclosed thereinand leached regions in other regions as disclosed herein.

Following sintering, various materials, such as a metal-solventcatalyst, remaining in interstitial regions within the as-sintered PCDbody may reduce the thermal stability of superabrasive table 14 atelevated temperatures. In some examples, differences in thermalexpansion coefficients between diamond grains in the as-sintered PCDbody and a metal-solvent catalyst in interstitial regions between thediamond grains may weaken portions of superabrasive table 14 that areexposed to elevated temperatures, such as temperatures developed duringdrilling and/or cutting operations. The weakened portions ofsuperabrasive table 14 may be excessively worn and/or damaged during thedrilling and/or cutting operations.

Removing the metal-solvent catalyst and/or other materials from theas-sintered PCD body may improve the heat resistance and/or thermalstability of superabrasive table 14, particularly in situations wherethe PCD material may be exposed to elevated temperatures. Ametal-solvent catalyst and/or other materials may be removed from theas-sintered PCD body using any suitable technique, including, forexample, leaching. In at least one embodiment, a metal-solvent catalyst,such as cobalt, may be removed from regions of the as-sintered PCD body,such as regions adjacent to the working surfaces of superabrasive table14. Removing a metal-solvent catalyst from the as-sintered PCD body mayreduce damage to the PCD material of superabrasive table 14 caused byexpansion of the metal-solvent catalyst.

At least a portion of a metal-solvent catalyst, such as cobalt, as wellas other materials, may be removed from at least a portion of theas-sintered PCD body using any suitable technique, without limitation.For example, chemical and/or gaseous leaching may be used to remove ametal-solvent catalyst from the as-sintered PCD body up to a desireddepth from a surface thereof. The as-sintered PCD body may be leached byimmersion in an acid or acid solution, such as aqua regia, nitric acid,hydrofluoric acid, or subjected to another suitable process to remove atleast a portion of the metal-solvent catalyst from the interstitialregions of the PCD body and form superabrasive table 14 comprising a PCDtable. For example, the as-sintered PCD body may be immersed in an acidsolution for about 2 to about 7 days (e.g., about 3, 5, or 7 days) orfor a few weeks (e.g., about 4 weeks) depending on the process employed.

Even after leaching, a residual, detectable amount of the metal-solventcatalyst may be present in the at least partially leached superabrasivetable 14. It is noted that when the metal-solvent catalyst isinfiltrated into the diamond particles from a cemented tungsten carbidesubstrate including tungsten carbide particles cemented with ametal-solvent catalyst (e.g., cobalt, nickel, iron, or alloys thereof),the infiltrated metal-solvent catalyst may carry tungsten and/ortungsten carbide therewith and the as-sintered PCD body may include suchtungsten and/or tungsten carbide therein disposed interstitially betweenthe bonded diamond grains. The tungsten and/or tungsten carbide may beat least partially removed by the selected leaching process or may berelatively unaffected by the selected leaching process.

In some embodiments, only selected portions of the as-sintered PCD bodymay be leached, leaving remaining portions of resulting superabrasivetable 14 unleached. For example, some portions of one or more surfacesof the as-sintered PCD body may be masked or otherwise protected fromexposure to a leaching solution and/or gas mixture while other portionsof one or more surfaces of the as-sintered PCD body may be exposed tothe leaching solution and/or gas mixture. Other suitable techniques maybe used for removing a metal-solvent catalyst and/or other materialsfrom the as-sintered PCD body or may be used to accelerate a chemicalleaching process. For example, exposing the as-sintered PCD body toheat, pressure, electric current, microwave radiation, and/or ultrasoundmay be employed to leach or to accelerate a chemical leaching process,without limitation. Following leaching, superabrasive table 14 maycomprise a volume of PCD material that is at least partially free orsubstantially free of a metal-solvent catalyst.

The plurality of diamond particles used to form superabrasive table 14comprising the PCD material may exhibit one or more selected sizes. Theone or more selected sizes may be determined, for example, by passingthe diamond particles through one or more sizing sieves or by any othermethod. In an embodiment, the plurality of diamond particles may includea relatively larger size and at least one relatively smaller size. Asused herein, the phrases “relatively larger” and “relatively smaller”refer to particle sizes determined by any suitable method, which differby at least a factor of two (e.g., 40 μm and 20 μm). More particularly,in various embodiments, the plurality of diamond particles may include aportion exhibiting a relatively larger size (e.g., 100 μm, 90 μm, 80 μm,70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 15 μm, 12 μm, 10 μm, 8 μm) andanother portion exhibiting at least one relatively smaller size (e.g.,30 μm, 20 μm, 15 μm, 12 μm, 10 μm, 8 μm, 4 μm, 2 μm, 1 μm, 0.5 μm, lessthan 0.5 μm, 0.1 μm, less than 0.1 μm). In another embodiment, theplurality of diamond particles may include a portion exhibiting arelatively larger size between about 40 μm and about 15 μm and anotherportion exhibiting a relatively smaller size between about 12 μm and 2μm. Of course, the plurality of diamond particles may also include threeor more different sizes (e.g., one relatively larger size and two ormore relatively smaller sizes) without limitation. Different sizes ofdiamond particle may be disposed in different locations within apolycrystalline diamond volume, without limitation. According to atleast one embodiment, disposing different sizes of diamond particles indifferent locations may facilitate control of a leach depth, as will bedescribed in greater detail below.

FIGS. 3 and 4 illustrate an exemplary superabrasive element 110according to various embodiments. Superabrasive element 110 may comprisea superabrasive table 114 that is not attached to a substrate. As shownin FIGS. 3 and 4 , superabrasive element 110 may include a rear surface118, a superabrasive face 120, and a peripheral surface 115 formed bysuperabrasive table 114. Superabrasive element 110 may also comprise achamfer 124 (i.e., sloped or angled) and/or any other suitable surfaceshape at the intersection of peripheral surface 115 and superabrasiveface 120, including, without limitation, an arcuate surface (e.g., aradius, an ovoid shape, or any other rounded shape), a sharp edge,multiple chamfers/radii, a honed edge, and/or combinations of theforegoing. At least one edge, such as an edge 130 and/or or an edge 131,may be formed at the intersection of chamfer 124 and each ofsuperabrasive face 120 and peripheral surface 115, respectively.Peripheral surface 115 of superabrasive element 110 may radiallysurround a central axis 128 of superabrasive element 110.

According to various embodiments, superabrasive element 110 may alsocomprise a rear chamfer 119. For example, a rear chamfer 119 comprisingan angular and/or rounded edge may be formed by superabrasive element110 at the intersection of peripheral surface 115 and rear surface 118.Any other suitable surface shape may also be formed at the intersectionof peripheral surface 115 and rear surface 118, including, withoutlimitation, an arcuate surface (e.g., a radius, an ovoid shape, or anyother rounded shape), a sharp edge, multiple chamfers/radii, a honededge, and/or combinations of the foregoing.

Superabrasive element 110 may be formed using any suitable technique,including, for example, HPHT sintering, as described above. In someexamples, superabrasive element 110 may be created by first forming asuperabrasive element 10 that includes a substrate 12 and asuperabrasive table 14, as detailed above in reference to FIGS. 1 and 2. Once superabrasive element 10 has been produced, superabrasive table14 may be separated from substrate 12 to form superabrasive element 110.For example, prior to or following leaching, superabrasive table 14 maybe separated from substrate 12 using any suitable process, including alapping process, a grinding process, a wire-electrical-dischargemachining (“wire EDM”) process, or any other suitable material-removalprocess, without limitation.

According to some embodiments, superabrasive element 110 may beprocessed and utilized either with or without an attached substrate. Forexample, following leaching, superabrasive element may be secureddirectly to a cutting tool, such as a drill bit, or to a bearingcomponent, such as a rotor or stator. In various embodiments, followingprocessing, superabrasive element 110 may be attached to a substrate.For example, rear surface 118 of superabrasive element 110 may bebrazed, welded, soldered, threadedly coupled, and/or otherwise adheredand/or fastened to a substrate, such as tungsten carbide substrate orany other suitable substrate, without limitation. Polycrystallinediamond elements having pre-sintered polycrystalline diamond bodiesincluding an infiltrant, such as those disclosed in U.S. Pat. No.8,323,367, the disclosure of which is incorporated herein, in itsentirety, by this reference, may be leached a second time as disclosedherein after reattachment of the pre-sintered polycrystalline diamondbodies.

FIGS. 5 and 6 illustrate exemplary superabrasive elements that includeleached volumes according to some embodiments. As shown in FIG. 5 , asuperabrasive element 210 may include a substrate 212 and asuperabrasive table 214 together forming a rear surface 218, asuperabrasive face 220, and a peripheral surface 215. Superabrasivetable 214 may also form a chamfer 224 and one or more cutting edges,such as edge 230 and edge 231, adjacent to chamfer 224. Superabrasivetable 214 may be affixed to substrate 212 at interface 226, which may bea planar or nonplanar interface.

As illustrated in FIG. 5 , superabrasive table 214 may include a firstvolume 232 comprising an interstitial material and a second volume 234having a lower concentration of the interstitial material than firstvolume 232. For example, superabrasive table 214 may comprise apolycrystalline diamond material having a matrix defining interstitialregions including one or more interstitial materials. Portions ofsuperabrasive table 214, such as second volume 234 may be leached orotherwise processed to remove interstitial materials, such as ametal-solvent catalyst, from the interstitial regions. Second volume 234may be created during leaching of superabrasive table 214 according toany suitable leaching technique. For example, portions of superabrasiveelement 210 may be masked and/or otherwise covered during at least apart of a leaching process to prevent a leaching solution fromcontacting selected portions of superabrasive element 210 (see, e.g.,FIGS. 15-18 ). In some embodiments, superabrasive element 210 may firstbe leached, after which portions of superabrasive element 210 may beremoved to modify the shape of first volume 232 and/or second volume 234according to one or more methods discussed herein (see, e.g., FIGS. 7-14).

A boundary region 235 may extend between first volume 232 and secondvolume 234 so as to border at least a portion of first volume 232 andsecond volume 234. Boundary region 235 may include amounts of aninterstitial material varying between an amount of the interstitialmaterial in first volume 232 and an amount of the interstitial materialin second volume 234. In other embodiments, the boundary may be welldefined (i.e., boundary region 235 may be thin compared to a depth ofsecond volume 234). As illustrated in FIG. 5 , first volume 232 may belocated adjacent to a central portion of superabrasive face 220. Forexample, first volume 232 may be disposed about central axis 228. Firstvolume 232 may extend between interface 226 and superabrasive face 220,with first volume 232 forming at least a portion of superabrasive face220 such that the central portion of superabrasive face 220 locatedabout central axis 228 is defined by first volume 232, as shown in FIG.5 . In additional embodiments, first volume 232 and superabrasive face220 may be separated by a thin layer of leached polycrystalline diamondmaterial located adjacent to a central region of superabrasive face 220(see, e.g., FIG. 11 ).

Second volume 234 may be formed around at least a portion of firstvolume 232. For example, second volume 234 may comprise an annularvolume surrounding at least a portion of first volume 232 such that theouter portion of superabrasive face 220 relative to central axis 228 isdefined by second volume 234. As shown in FIG. 5 , second volume 234 maybe located adjacent to superabrasive face 220 and/or superabrasivechamfer 224 so as to at least partially surround a portion of firstvolume 232, such as a portion of first volume 232 adjacent tosuperabrasive face 220. Second volume 234 may additionally be locatedadjacent to peripheral surface 215. Second volume 234 may be separatedfrom interface 226 adjacent to substrate 212 so as to prevent corrosionof substrate 212 by a leaching solution used to form second volume 234.

First volume 232, second volume 234, and boundary region 235 may beformed to any suitable size and/or shape within superabrasive table 214,without limitation. For example, boundary region 235 may extend along agenerally straight, angular, curved, and/or variable (e.g., zigzag,undulating) profile between first volume 232 and second volume 234. Invarious embodiments, boundary region 235 may comprise a relativelynarrow region between first volume 232 and second volume 234, whileboundary region 235 may optionally comprise a relatively wider regionbetween first volume 232 and second volume 234. For example, boundaryregion 235 may extend from superabrasive side surface side surface 222to superabrasive face 220.

According to some embodiments, boundary region 235 may comprise a firstboundary portion 235 a extending inward from superabrasive face 220 anda second boundary portion 235 b extending inward from superabrasive sidesurface 222. For example, as shown in FIG. 5 , first boundary portion235 a may extend in a direction that is substantially perpendicular tosuperabrasive face 220. Additionally, second boundary portion 235 b mayextend in a direction that is substantially perpendicular tosuperabrasive side surface 222. First boundary portion 235 a and secondboundary portion 235 b may also extend in any other suitable directions,without limitation. First boundary portion 235 a and second boundaryportion 235 b may intersect at a boundary junction 235 c. As illustratedin FIG. 5 , boundary junction 235 c may be disposed at a depth 240relative to chamfer 224. Depth 240 may be measured, for example, in adirection perpendicular to chamfer 224.

As shown in FIG. 5 , second volume 234 may have a depth 236 fromsuperabrasive face 220 in a direction substantially perpendicular tosuperabrasive face 220. Second volume 234 may comprise a generallyannular-shaped volume defined between a first diameter 237 and a seconddiameter 238 surrounding central axis 228. The portion of first volume232 surrounded by second volume 234 may be generally defined by firstdiameter 237. Second diameter 238 may represent a diameter of peripheralsurface 215. Additionally, edge 230 formed at the intersection ofchamfer 224 and superabrasive face 220 may be located at a thirddiameter 239 relative to central axis 228. The generally annular-shapedsecond volume 234 may comprise a generally ring-shaped volume that isnot perfectly symmetric but is irregular in one or more dimensions (aswill be discussed in greater detail below with reference to FIGS. 27Aand 27B).

According to various embodiments, a percentage ratio of first diameter237 to second diameter 238 may be greater than approximately 10%. Forexample, a percentage ratio of first diameter 237 to second diameter 238may be between approximately 10% and approximately 50% (e.g.,approximately 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%). Inanother example, a percentage ratio of first diameter 237 to seconddiameter 238 may be between approximately 30% and approximately 95%(e.g., approximately 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%,80%, 85%, 90%, or 95%). Additionally, according to at least oneembodiment, a percentage ratio of first diameter 237 to third diameter239 may be greater than approximately 10%. For example, a percentageratio of first diameter 237 to third diameter 239 may be betweenapproximately 10% and approximately 50% (e.g., approximately 10%, 15%,20%, 25%, 30%, 35%, 40%, 45%, or 50%). In another example, a percentageratio of first diameter 237 to third diameter 239 may be betweenapproximately 30% and approximately 95% (e.g., approximately 30%, 35%,40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%).

Second volume 234 may be leached to any suitable depth fromsuperabrasive face 220, chamfer 224, and/or superabrasive side surface222, without limitation. According to some embodiments, second volume234 may have a leach depth greater than or equal to approximately 200 μmas measured in a substantially perpendicular direction from at least oneof superabrasive face 220, chamfer 224, and/or superabrasive sidesurface 222. In various embodiments, second volume 234 may have a leachdepth between approximately 200 μm and approximately 1200 μm (e.g.,approximately 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm,550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm,1000 μm, 1050 μm, 1100 μm, 1150 μm, or 1200 μm) as measured in asubstantially perpendicular direction from at least one of superabrasiveface 220, chamfer 224, and/or superabrasive side surface 222. Accordingto at least one embodiment, a depth 240 of second volume 234 as measuredfrom a center portion of chamfer 224 and/or from boundary junction 235 cin a direction perpendicular to chamfer 224 may be between approximately200 μm and 700 μm. According to various embodiments, a percentage ratioof the difference between second diameter 238 and first diameter 237(i.e., first diameter 237 subtracted from second diameter 238) to depth236 of second volume 234 may be between approximately 70% andapproximately 130% (e.g., approximately 70%, 80%, 90%, 100%, 110%, 120%,or 130%). For example, a percentage ratio of the difference between asecond diameter 238 of 4500 μm and a first diameter 237 of 3700 μm to adepth 236 of 700 μm may be 114% based on the calculation ((4500 μm−3700μm)/700 μm)*100%.

Superabrasive elements 210 having superabrasive table 214 comprisingfirst volume 232 and second volume 234 may exhibit properties ofincreased thermal stability, fatigue resistance, strength, and/or wearresistance. Such properties may be enhanced by the shape, size, and/orlocations of first volume 232, second volume 234, and/or boundary region235 of superabrasive table 214. Accordingly, the superabrasive elementconfiguration illustrated in FIG. 5 , as well as other configurationsillustrated and described herein, may provide significant resistance toundesired spalling, cracking, and/or thermal damage of superabrasiveportions, such as superabrasive table 214, of the superabrasive elementsduring drilling.

FIG. 6 shows an exemplary superabrasive element 310 according to atleast one embodiment. As shown in FIG. 6 , a superabrasive element 310may include a substrate 312 and a superabrasive table 314 togetherforming a rear surface 318, a superabrasive face 320, and a peripheralsurface 315. Superabrasive table 314 may also form a chamfer 324 and oneor more cutting edges, such as edge 330 and edge 331, adjacent tochamfer 324. Superabrasive table 314 may be affixed to substrate 312 atinterface 326, which may be a planar or nonplanar interface.

As illustrated in FIG. 6 , superabrasive table 314 may include a firstvolume 332 comprising an interstitial material and a second volume 334having a lower concentration of the interstitial material than firstvolume 332. Portions of superabrasive table 314, such as second volume334 may be leached or otherwise processed to remove interstitialmaterials, such as a metal-solvent catalyst, from the interstitialregions. Second volume 334 may be created during leaching ofsuperabrasive table 314 according to any suitable leaching technique.For example, portions of superabrasive element 310 may be masked and/orotherwise covered during at least a part of a leaching process toprevent a leaching solution from contacting selected portions ofsuperabrasive element 310 (see, e.g., FIGS. 15-18 ). In someembodiments, superabrasive element 310 may first be leached, after whichportions of superabrasive element 310 may be removed to modify the shapeof first volume 332 and/or second volume 334 according to one or moremethods discussed herein (see, e.g., FIGS. 7-14 ).

A boundary region 335 may extend between first volume 332 and secondvolume 334. Boundary region 335 may include amounts of metal-solventcatalyst varying between an amount of metal-solvent catalyst in firstvolume 332 and an amount of metal-solvent catalyst in second volume 334.As illustrated in FIG. 6 , first volume 332 may be located adjacent to acentral portion of superabrasive face 320. For example, first volume 332may be disposed about central axis 328. First volume 332 may extendbetween interface 326 and superabrasive face 320 with first volume 332forming at least a portion of superabrasive face 320 such that thecentral portion of superabrasive face 320 located about central axis 328is defined by first volume 332, as shown in FIG. 6 . In someembodiments, first volume 332 and superabrasive face 320 may beseparated by a thin layer of leached polycrystalline diamond materiallocated adjacent to a central region of superabrasive face 320 (see,e.g., FIG. 11 ).

Second volume 334 may be formed around at least a portion of firstvolume 332. For example, second volume 334 may comprise an annularvolume surrounding at least a portion of first volume 332 such that anouter portion of superabrasive face 320 relative to central axis 328 isdefined by second volume 334. As shown in FIG. 6 , second volume 334 maybe located adjacent to superabrasive face 320 and/or superabrasivechamfer 324 so as to at least partially surround a portion of firstvolume 332 that is also adjacent to superabrasive face 320. Secondvolume 334 may additionally be located adjacent to peripheral surface315. Second volume 334 may be separated from interface 326 adjacent tosubstrate 312 so as to prevent corrosion of substrate 312 by a leachingsolution used to form second volume 334.

First volume 332, second volume 334, and boundary region 335 may beformed to any suitable size and/or shape within superabrasive table 314,without limitation. For example, boundary region 335 may extend along agenerally straight, angular, curved, and/or variable (e.g., zigzag,undulating) profile between first volume 332 and second volume 334. Invarious embodiments, boundary region 335 may comprise a relativelynarrow region between first volume 332 and second volume 334, whileboundary region 335 may optionally comprise a relatively wider regionbetween first volume 332 and second volume 334. For example, boundaryregion 335 may extend from superabrasive side surface side surface 322to superabrasive face 320, as shown in FIG. 5 . According to someembodiments, boundary region 335 may comprise a first boundary portion335 a extending inward from superabrasive face 320 and a second boundaryportion 335 b extending inward from superabrasive side surface 322.

For example, as shown in FIG. 6 , first boundary portion 335 a mayextend inward from superabrasive face 320 along a sloping and/or arcuateprofile. Additionally, second boundary portion 335 b may extend inwardfrom superabrasive side surface 322 along a sloping and/or arcuateprofile. First boundary portion 335 a and second boundary portion 335 bmay also extend in any other suitable directions, without limitation.First boundary portion 335 a and second boundary portion 235 b mayintersect at a boundary junction 335 c. As illustrated in FIG. 6 ,boundary junction 335 c may be disposed at a depth 340 relative tochamfer 324. Depth 340 may be measured, for example, in a directionperpendicular to chamfer 324.

As shown in FIG. 6 , second volume 334 may have a depth 336 fromsuperabrasive face 320 in a direction substantially perpendicular tosuperabrasive face 320. Second volume 334 may comprise a generallyannular-shaped volume defined between a first diameter 337 and a seconddiameter 338 surrounding central axis 328. The portion of first volume332 surrounded by second volume 334 may be generally defined by firstdiameter 337. Second diameter 338 may represent a diameter of peripheralsurface 215. Additionally, edge 330 formed at the intersection ofchamfer 324 and superabrasive face 320 may be located at a thirddiameter 339 relative to central axis 328.

According to various embodiments, a percentage ratio of first diameter337 to second diameter 338 may be greater than approximately 10%. Forexample, a percentage ratio of first diameter 337 to second diameter 338may be between approximately 10% and approximately 50% (e.g.,approximately 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%). Inanother example, a percentage ratio of first diameter 337 to seconddiameter 338 may be between approximately 30% and approximately 95%(e.g., approximately 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%,80%, 85%, 90%, or 95%). Additionally, according to at least oneembodiment, a percentage ratio of first diameter 337 to third diameter339 may be greater than approximately 10%. For example, a percentageratio of first diameter 337 to third diameter 339 may be betweenapproximately 10% and approximately 50% (e.g., approximately 10%, 15%,20%, 25%, 30%, 35%, 40%, 45%, or 50%). In another example, a percentageratio of first diameter 337 to third diameter 339 may be betweenapproximately 30% and approximately 95% (e.g., approximately 30%, 35%,40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%).

Second volume 334 may be leached to any suitable depth fromsuperabrasive face 320, chamfer 324, and/or superabrasive side surface322, without limitation. According to some embodiments, second volume334 may have a leach depth greater than or equal to approximately 200 μmas measured in a substantially perpendicular direction from at least oneof superabrasive face 320, chamfer 324, and/or superabrasive sidesurface 322. In various embodiments, second volume 334 may have a leachdepth between approximately 200 μm and approximately 1200 μm (e.g.,approximately 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm,550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm,1000 μm, 1050 μm, 1100 μm, 1150 μm, or 1200 μm) as measured in asubstantially perpendicular direction from at least one of superabrasiveface 320, chamfer 324, and/or superabrasive side surface 322. Accordingto at least one embodiment, a depth 340 of second volume 334 as measuredfrom a center portion of chamfer 324 and/or from boundary junction 335 cin a direction perpendicular to chamfer 324 may be between approximately200 μm and 700 μm. According to various embodiments, a percentage ratioof the difference between second diameter 338 and first diameter 337(i.e., first diameter 337 subtracted from second diameter 338) to depth336 of second volume 334 may be between approximately 70% andapproximately 130% (e.g., approximately 70%, 80%, 90%, 100%, 110%, 120%,or 130%). For example, a percentage ratio of the difference between asecond diameter 338 of 4500 μm and a first diameter 337 of 4100 μm to adepth 336 of 500 μm may be 80% based on the calculation ((4500 μm−4100μm)/500 μm)*100%.

Superabrasive elements 310 having superabrasive table 314 comprisingfirst volume 332 and second volume 334 may exhibit properties ofincreased thermal stability, fatigue resistance, strength, and/or wearresistance. Such properties may be enhanced by the shape, size, and/orlocations of first volume 332, second volume 334, and/or boundary region335 of superabrasive table 314. Accordingly, the superabrasive elementconfiguration illustrated in FIG. 6 , as well as other configurationsillustrated and described herein, may provide significant resistance toundesired spalling, cracking, and/or thermal damage of superabrasiveportions, such as superabrasive table 314, of the superabrasive elementsduring drilling.

FIGS. 7-11 illustrate a superabrasive element at various stages ofleaching and processing according to at least one embodiment. FIG. 7 isa perspective view of a superabrasive element 410 and FIG. 8 is across-sectional view of superabrasive element 410 prior to leaching. Asshown in FIGS. 7 and 8 , superabrasive element 410 may include asubstrate 412 and a superabrasive table 414 together forming a rearsurface 418, a superabrasive face 420, and a peripheral surface 415.Superabrasive table 414 may be affixed to substrate 412 at interface426, which may be a planar or nonplanar interface. Prior to exposure toa leaching agent, superabrasive table 414 may comprise an unleachedvolume of superabrasive material, such as a polycrystalline diamond bodycontaining a metal-solvent catalyst disposed in interstitial regions.

Superabrasive element 410 may be formed to include a peripheral recess442 defined in superabrasive table 414 and extending circumferentiallyaround at least a peripheral portion of superabrasive table 414. Forexample, peripheral recess 442 may be defined between superabrasive face420 and superabrasive side surface 422. Peripheral recess 442 may beformed in superabrasive element 410 using any suitable technique,without limitation. According to at least one embodiment, peripheralrecess 442 may be formed during sintering of a diamond particle volumeto form superabrasive table 414 comprising a polycrystalline diamondmaterial. For example, a container surrounding the diamond particlevolume during sintering, such as a sintering can, may include aninterior protrusion or feature for molding peripheral recess 442 insuperabrasive element 410. In additional embodiments, peripheral recess442 may be formed following sintering of superabrasive element 410. Forexample, peripheral recess 442 may be formed by machining, laserablation, grinding, and/or otherwise removing selected portions ofsuperabrasive table 414 of superabrasive element 410. Portions ofsuperabrasive table 414 may be removed through, for example, milling,grinding, lapping, centerless grinding, turning, and/or any othersuitable mechanical and/or chemical processing technique. Material maybe removed from superabrasive table 414 to form peripheral recess 442 orany geometrical feature by using any suitable technique, including, byway of example, laser cutting or ablation, electrical dischargemachining, electro-chemical erosion, water jet cutting, and/or abrasivewater jet machining.

Peripheral recess 442 may comprise any desired shape, withoutlimitation. For example, peripheral recess 442 may be defined byangular, straight, and/or arcuate surface portions of superabrasivetable 414. In at least one embodiment, peripheral recess 442 may bedefined by a first surface portion 442 a and a second surface portion442 b intersecting first surface portion 442 a. Peripheral recess 442may be formed circumferentially about a portion of superabrasive table414 that is adjacent to superabrasive face 420, as shown in FIG. 7 .Peripheral recess 442 may, for example, be generally centered aboutcentral axis 428.

FIGS. 9A and 9B illustrate superabrasive element 410 following exposureto a leaching agent, such as a corrosive leaching solution. As shown inFIGS. 9A and 9B, a peripheral recess 442 may result in a generallysloped and/or undulating leach profile in portions of superabrasivetable 414 near peripheral recess 442. Leach depths of superabrasivetable may be relatively deeper in portions of superabrasive table 414adjacent to an intersection of first surface portion 442 a andsuperabrasive face 420 and/or portions of superabrasive table 414adjacent to an intersection of second surface portion 442 b andsuperabrasive side surface 422. Such leach depths may define a generallysloping leach profile between superabrasive side surface 422 and aregion of superabrasive table 414 near superabrasive face 420.

As shown in FIGS. 9A and 9B, leaching superabrasive element 410 mayproduce a first volume 432 (i.e., unleached volume) comprising aninterstitial material, such as a metal-solvent catalyst, and a secondvolume 434 (i.e., leached volume) having a lower concentration of theinterstitial material than first volume 432. A boundary region 435 mayextend between first volume 432 and second volume 434. Boundary region435 may include amounts of an interstitial material varying between anamount of the interstitial material in first volume 432 and an amount ofthe interstitial material in second volume 434. In other embodiments,the boundary may be well defined (i.e., boundary region 435 may be thincompared to a depth of second volume 434). As illustrated in FIGS. 9Aand 9B, at least a portion of boundary region 435, such as slopedboundary portion 445, may generally slope between superabrasive sidesurface 422 and a region of superabrasive table 414 near superabrasiveface 420 at an oblique angle relative to central axis 428. Additionally,at least a portion of boundary region 435 adjacent to superabrasive face420, such as a central boundary portion 444 of boundary region 435disposed about central axis 428, may extend in a direction generallyparallel to superabrasive face 420.

In some embodiments, as shown, for example, in FIG. 9B, boundary region435 may have a different profile shape and/or may intersect a differentportion of superabrasive side surface 422 in comparison with boundaryregion 435 illustrated in FIG. 9A. Additionally, second volume 434 shownin FIG. 9B may have a greater leach depth relative to various portionsof superabrasive table 412, such as peripheral recess 442, than secondvolume 434 shown in FIG. 9A. Any combination of features, methods, orembodiments described herein (e.g., leachability, masking, removingmaterial prior to and/or following leaching) may be utilized to form thedifferent second volumes 434 and boundary regions 435 illustrated inFIGS. 9A and 9B.

The present invention contemplates selectively removing portions (e.g.,leached regions) of the diamond table to tailor the shape and/or size ofthe remaining leached regions of the diamond table.

FIG. 10 illustrates superabrasive element 410 following furtherprocessing of the previously leached superabrasive element 410 (seeFIGS. 9A and 9B) to remove portions of exterior material fromsuperabrasive element 410. According to various embodiments,superabrasive element 410 may be further processed using any suitablematerial removal technique, without limitation. For example, portions ofsuperabrasive element 410 may be smoothed and/or polished using anysuitable mechanical, chemical, electrical, and/or laser processingtechnique, including grinding, lapping, milling, polishing, and/or anyother suitable mechanical processing technique. By way of example, U.S.Pat. Nos. 5,967,250; 6,145,608; 5,653,300; 5,447,208; and 5,944,129, thedisclosure of each of which is incorporated herein, in its entirety, bythis reference, disclose superabrasive elements having smoothed surfaceportions.

According to at least one embodiment, material may be removed from atleast a region adjacent to superabrasive face 420, first surface portion442 a, and/or second surface portion 442 b of superabrasive table 414.Material may also be removed from at least a region adjacent toperipheral surface 415, such as a region adjacent to superabrasive sidesurface 422. As shown in FIG. 10 , sufficient material may be removedfrom superabrasive table 414 that peripheral recess 442 is no longerdefined in superabrasive table 414. Additionally, according to variousembodiments, a superabrasive chamfer 424 may be formed on a portion ofsuperabrasive table 414 between superabrasive face 420 and superabrasiveside surface 422.

Boundary region 435 located between first volume 432 and second volume434 may extend along any suitable profile within superabrasive table414. For example, as illustrated in FIG. 10 , a sloped boundary portion445 of boundary region 435 may extend between superabrasive face 420 andsuperabrasive side surface 422 along any suitable profile, including,for example, a generally straight, angular, curved, and/or variable(e.g., zigzag, undulating) profile. According to at least oneembodiment, superabrasive element 410 may be processed such thatboundary region 435 intersects superabrasive face 420. Accordingly, asshown in FIG. 10 , first volume 432 may be located directly adjacent toa central portion of superabrasive face 420. For example, first volume432 may be disposed about central axis 428. First volume 432 may extendbetween interface 426 and superabrasive face 420, with first volume 432forming at least a portion of superabrasive face 420 such that at leastthe central portion of superabrasive face 420 located about central axis428 is defined by first volume 432.

In some embodiments, material may be removed from superabrasive element410 such that first volume 432 and superabrasive face 420 are separatedby a thin layer comprising a portion of second volume 434. For example,as illustrated in FIG. 11 , a thin layer portion 446 of second volume434 may extend adjacent to at least a portion of superabrasive face 420so that first volume 432 is at least partially separated fromsuperabrasive face 420 by thin layer portion 446.

Any portion and/or portions of second volume 434 as shown in FIGS. 9Aand 9B may remain after removing other portions of the diamond table.Such a configuration may form a desirable size and/or shape of theremaining leached region(s) of the diamond table. As shown, for example,in FIG. 11 , boundary region 435 may have a different profile shapeand/or may intersect a different portion of superabrasive side surface422 in comparison with boundary region 435 illustrated in FIG. 10 . Anycombination of features, methods, or embodiments described herein (e.g.,leachability, masking, removing material prior to and/or followingleaching) may be utilized to form the boundary regions 435 illustratedin FIGS. 10 and 11 . In some embodiments, superabrasive element 410illustrated in FIG. 11 may be formed by processing superabrasive element410 illustrated in FIG. 9B. According to at least one embodiment,additional material may be removed from the outer periphery (i.e., outerperipheral surface 415) of superabrasive element 410 illustrated in FIG.11 in comparison with superabrasive element 410 illustrated in FIG. 10 .

While FIGS. 7-9 described in detail above illustrate a peripheral recess442 formed between superabrasive face 420 and peripheral surface 415 anda leach profile within superabrasive element 410 resulting from such aconfiguration, peripheral recess 442 may optionally be formed to anysuitable size, shape, and/or location so as to obtain a desired leachprofile.

FIGS. 12A-13 illustrate additional superabrasive elements at variousstages of leaching and processing according to certain embodiments.FIGS. 12A and 12B show a superabrasive element 510, and FIG. 13 showssuperabrasive element 510 following processing to remove portions ofsuperabrasive element 510. As shown in FIGS. 12A-13 , superabrasiveelement 510 may include a substrate 512 and a superabrasive table 514together forming a rear surface 518, a superabrasive face 520, and aperipheral surface 515. Superabrasive table 514 is bonded to substrate512 along interface 526, which may be a planar or nonplanar interface.Prior to exposure to a leaching agent, superabrasive table 514 maycomprise an unleached volume of superabrasive material, such as apolycrystalline diamond body containing a metal-solvent catalystdisposed in interstitial regions.

Superabrasive element 510 may be formed to include a central recess 547defined in at least a portion of superabrasive table 514. For example,central recess 547 may be defined by a top portion of superabrasivetable 514. According to at least one example, as shown in FIGS. 12A and12B, central recess 547 may be defined by superabrasive face 520 and aperipheral rim 548 extending circumferentially around at least a portionof central recess 547. Peripheral rim 548 may slope upward and radiallyoutward from superabrasive face 520. For example, peripheral rim 548 maycomprise a sloped surface 549 sloping obliquely from superabrasive face520 and intersecting superabrasive side surface 522. Central recess 547may optionally be formed to any other suitable size, shape, and/orconfiguration within superabrasive table 514 so as to obtain a desiredleach profile, without limitation.

Central recess 547 may be formed in superabrasive element 510 using anysuitable technique. According to at least one embodiment, central recess547 may be formed during sintering of a diamond particle volume to formsuperabrasive table 514. For example, a container surrounding thediamond particle volume during sintering, such as a sintering can, mayinclude an interior protrusion, feature, or insert (e.g., h-BN,graphite, a material suitable for use in a polycrystalline diamondsintering gasket, or other suitable material) within the sintering canfor molding central recess 547 in superabrasive element 510. Inadditional embodiments, central recess 547 may be formed followingsintering of superabrasive element 510. For example, central recess 547may be formed by machining and/or otherwise removing selected portionsof superabrasive table 514 of superabrasive element 510. Portions ofsuperabrasive table 514 may be removed through, for example, milling,grinding, turning, drilling, and/or any other suitable mechanical and/orchemical processing technique. Material also may be removed fromsuperabrasive table 514 using any other suitable technique, including,by way of example, laser cutting, electrical discharge machining,electro-chemical erosion, water jet cutting, and/or abrasive water jetmachining.

As illustrated in FIG. 12B, following exposure to a leaching agent,superabrasive table 514 may include a first volume 532 (i.e., unleachedvolume) comprising an interstitial material, such as a metal-solventcatalyst, and a second volume 534 (i.e., leached volume) having a lowerconcentration of the interstitial material than first volume 532. Aboundary region 535 may extend between first volume 532 and secondvolume 534. Boundary region 535 may include amounts of an interstitialmaterial varying between an amount of the interstitial material in firstvolume 532 and an amount of the interstitial material in second volume534. In other embodiments, the boundary may be well defined (i.e.,boundary region 535 may be thin compared to a depth of second volume534). As illustrated in FIG. 12B, boundary region 535 may include acentral boundary portion 544 and a sloped boundary portion 545. Slopedboundary portion 545 may generally slope between superabrasive sidesurface 522 and central boundary portion 544 at an oblique anglerelative to central axis 528. For example, at least a portion of slopedboundary portion 545 may slope in a direction generally parallel tosloped surface 549, while a portion of sloped boundary portion 545 mayfollow a generally arcuate profile at an intersection of sloped boundaryportion 545 and central boundary portion 544.

In some embodiments, boundary region 535 may have different profileshapes and/or may intersect different portions of superabrasive sidesurface 522. For example, as illustrated in FIG. 12B, boundary region535 may alternatively be formed to follow profile P₁, P₂, and/or anyother suitable profile, without limitation. Any combination of features,methods, or embodiments described herein (e.g., leachability, masking,removing material prior to and/or following leaching) may be utilized toform various boundary region 535 profiles.

FIGS. 13A and 13B illustrate superabrasive element 510 following furtherprocessing of the previously leached superabrasive element 510 to removeportions of exterior material from superabrasive element 510. Accordingto various embodiments, superabrasive element 510 may be furtherprocessed using any suitable material removal technique, withoutlimitation. For example, portions of superabrasive element 510 may besmoothed and/or polished using any suitable mechanical, chemical,electrical, and/or laser processing technique, including grinding,lapping, milling, polishing, and/or any other suitable mechanicalprocessing technique.

According to at least one embodiment, material may be removed from atleast regions adjacent to superabrasive face 520. Material may also beremoved from at least a region adjacent to peripheral surface 515, suchas a region adjacent to superabrasive side surface 522. Peripheral rim548 extending from superabrasive face 520, as illustrated in FIGS. 12Aand 12B, may be removed so that superabrasive face 520 is the top-mostsurface of superabrasive element 510. As shown in FIGS. 13A and 13B, asuperabrasive chamfer 524 may be formed on a portion of superabrasivetable 514 between superabrasive face 520 and superabrasive side surface522.

Boundary region 535 located between first volume 532 and second volume534 may extend along any suitable profile within superabrasive table514. For example, as illustrated in FIG. 13A, sloped boundary portion545 of boundary region 535 may extend between superabrasive chamfer 524and central boundary portion 544 along any suitable profile, including,for example, a generally straight, angular, curved, and/or variable(e.g., zigzag, undulating) profile. According to at least oneembodiment, superabrasive element 510 may be processed such thatboundary region 535 intersects superabrasive chamfer 524 and/or asurface region adjacent to superabrasive chamfer 524 (e.g.,superabrasive side surface 522). Accordingly, as shown in FIG. 13A,second volume 534 may be located directly adjacent to a central portionof superabrasive face 520. For example, second volume 534 may bedisposed about central axis 528. A portion of first volume 532, such asa portion adjacent to superabrasive chamfer 524, may peripherallysurround at least a portion of second volume 534.

In some embodiments, as illustrated in FIG. 13B, sloped boundary portion545 of boundary region 535 may extend between superabrasive side surface522 and central boundary portion 544 along any suitable profile,including, for example, a generally straight, angular, curved, and/orvariable (e.g., zigzag, undulating) profile. According to at least oneembodiment, superabrasive element 510 may be processed such thatboundary region 535 intersects superabrasive side surface 522 belowsuperabrasive chamfer 524.

FIGS. 14A-14F illustrate a superabrasive element 610 according tovarious embodiments. As shown in FIGS. 14A and 14B, superabrasiveelement 610 may include a substrate 612 and a superabrasive table 614together forming a rear surface 618, a superabrasive face 620, and aperipheral surface 615. Superabrasive table 614 is bonded to substrate612 along interface 626, which may be a planar or nonplanar interface.Prior to exposure to a leaching agent, superabrasive table 614 maycomprise an unleached volume of superabrasive material, such as apolycrystalline diamond body containing a metal-solvent catalystdisposed in interstitial regions. The region labeled “A” corresponds toa portion of superabrasive element 610, as illustrated in each of FIGS.14D-14F, following further processing in accordance with one or moremethods described herein.

Superabrasive element 610 may be formed to include a central recess 647defined in at least a portion of superabrasive table 614. Central recess647 may be defined by a top portion of superabrasive table 614.According to at least one example, as shown in FIGS. 14A and 14B,central recess 647 may be defined by superabrasive face 620 and aperipheral rim 648 extending circumferentially around at least a portionof central recess 647. According to various embodiments, peripheral rim648 may slope upward from superabrasive face 620. For example,peripheral rim 648 may comprise a side surface 650 extending upward fromsuperabrasive face 620. In some embodiments, side surface 650 may extendin a direction generally parallel to central axis 628 and/or generallyperpendicular to superabrasive face 620. Central recess 647 may compriseany desired shape, without limitation.

Central recess 647 may be formed in superabrasive element 610 using anysuitable technique, without limitation. According to at least oneembodiment, central recess 647 may be formed during sintering of adiamond particle volume to form superabrasive table 614. For example, acontainer surrounding the diamond particle volume during sintering, suchas a sintering can, may include an interior protrusion, feature, orinsert (e.g., h-BN, graphite, a material suitable for use in apolycrystalline diamond sintering gasket, or other suitable material)within the sintering can for molding central recess 647 in superabrasiveelement 610. In additional embodiments, central recess 647 may be formedfollowing sintering of superabrasive element 610. For example, centralrecess 647 may be formed by machining, laser ablation, grinding, and/orotherwise removing selected portions of superabrasive table 614 ofsuperabrasive element 610. Portions of superabrasive table 614 may beremoved through, for example, milling, grinding, lapping, centerlessgrinding, turning, drilling, and/or any other suitable mechanical and/orchemical processing technique. Material may be removed fromsuperabrasive table 614 using any other suitable technique, including,by way of example, laser cutting or ablation, electrical dischargemachining, electro-chemical erosion, water jet cutting, and/or abrasivewater jet machining.

As illustrated in FIG. 14B, following exposure to a leaching agent,superabrasive table 614 may include a first volume 632 (i.e., unleachedvolume) comprising an interstitial material, such as a metal-solventcatalyst, and a second volume 634 (i.e., leached volume) having a lowerconcentration of the interstitial material than first volume 632. Aboundary region 635 may extend between first volume 632 and secondvolume 634. Boundary region 635 may include amounts of an interstitialmaterial varying between an amount of the interstitial material in firstvolume 632 and an amount of the interstitial material in second volume634. In other embodiments, the boundary may be well defined (i.e.,boundary region 635 may be thin compared to a depth of second volume634). As illustrated in FIG. 14B, boundary region 635 may include acentral boundary portion 644 and a peripheral boundary portion 645.Peripheral boundary portion 645 may generally slope betweensuperabrasive side surface 622 and central boundary portion 644 at anoblique angle relative to central axis 628. A portion of peripheralboundary portion 645 may follow a generally arcuate profile at anintersection of peripheral boundary portion 645 and central boundaryportion 644.

In some embodiments, boundary region 635 may have different profileshapes and/or may intersect different portions of superabrasive sidesurface 622. For example, as illustrated in FIG. 14B (see also FIG.14F), boundary region 635 may alternatively be formed to follow profileP₁, P₂, P₃, and/or any other suitable profile, without limitation. Anycombination of features, methods, or embodiments described herein (e.g.,leachability, masking, removing material prior to and/or followingleaching) may be utilized to form various boundary region 635 profiles.

According to various embodiments, superabrasive element 610 may befurther processed using any suitable material removal technique, withoutlimitation. For example, portions of superabrasive element 610 may besmoothed and/or polished using any suitable mechanical, chemical,electrical, and/or laser processing technique, including grinding,lapping, milling, polishing, and/or any other suitable mechanicalprocessing technique. According to at least one embodiment, asillustrated in FIG. 14C, material may be removed from at least regionsadjacent to superabrasive face 620. For example, peripheral rim 648extending from superabrasive face 620, as illustrated in FIGS. 14A and14B, may be removed so that superabrasive face 620 is the top-mostportion of superabrasive element 610. In some embodiments, as shown inFIG. 14C, following removal of peripheral rim 648, superabrasive face620 may comprise a substantially planar face extending to superabrasiveside surface 622. Additionally, peripheral boundary portion 645 mayintersect superabrasive face 620. In additional embodiments, peripheralboundary portion 645 may intersect superabrasive side surface 622.

Material may also be removed from at least a region adjacent toperipheral surface 615, such as a region adjacent to superabrasive sidesurface 622, prior to and/or following removal of material from regionsadjacent to superabrasive face 620. For example, FIG. 14C showsexemplary depths G₁ and G₂ to which material may be removed fromperipheral surface 615 of superabrasive element 610.

According to at least one embodiment, as shown in FIG. 14D, material maybe removed from a periphery of superabrasive element 610 to a depth G₁.Additionally, a superabrasive chamfer 624 may be formed on a portion ofsuperabrasive table 614 between superabrasive face 620 and superabrasiveside surface 622. As illustrated in FIG. 14D, peripheral boundaryportion 645 may intersect superabrasive chamfer 624. Peripheral boundaryportion 645 may extend from superabrasive chamfer 624 to centralboundary portion 644, which may extend generally parallel tosuperabrasive face 620.

According to some embodiments, as shown in FIG. 14E, material may beremoved from a periphery of superabrasive element 610 to a depth G₂,which is deeper than depth G₁ shown in FIG. 14C. Additionally, asuperabrasive chamfer 624 may be formed on a portion of superabrasivetable 614 between superabrasive face 620 and superabrasive side surface622. As illustrated in FIG. 14E, peripheral boundary portion 645 mayintersect superabrasive side surface 622 at a region below superabrasivechamfer 624. Peripheral boundary portion 645 may extend fromsuperabrasive side surface 622 to central boundary portion 644, whichmay extend generally parallel to superabrasive face 620.

In some embodiments, at least a portion of peripheral rim 648 may beleft extending from superabrasive face 620 so as to define centralrecess 647 in superabrasive table 614 following processing ofsuperabrasive element 610. For example, as shown in FIG. 14F, subsequentto leaching of superabrasive element 610, portions of peripheral rim 648may be processed to form rounded corners 651 and 653 and superabrasivechamfer 624. For example, a convex corner at the intersection of aforward end 621 of peripheral rim 648 and side surface 650 may beprocessed to form rounded corner 651, and a concave corner at theintersection of superabrasive face 620 and side surface 650 may beprocessed to form rounded corner 653. Rounded corner 651 and/or roundedcorner 653 may be formed by machining, laser ablation, grinding, and/orotherwise removing selected portions of superabrasive table 614 ofsuperabrasive element 610. Portions of superabrasive table 614 may beremoved through, for example, milling, grinding, centerless grinding,turning, drilling, and/or any other suitable mechanical and/or chemicalprocessing technique. Material may be removed from superabrasive table614 using any other suitable technique, including, by way of example,laser cutting or ablation, electrical discharge machining,electro-chemical erosion, water jet cutting, and/or abrasive water jetmachining. Additionally, a superabrasive chamfer 624 may be formed on aportion of superabrasive table 614 between superabrasive face 620 andsuperabrasive side surface 622. In additional embodiments, roundedcorners 651 and 653 and/or superabrasive chamfer 624 may be formed onsuperabrasive table 614 prior to leaching.

As illustrated in FIG. 14F, boundary region 635 may alternatively beformed to follow profile P₁, P₂, P₃, and/or any other suitable profile,without limitation. Any combination of features, methods, or embodimentsdescribed herein (e.g., leachability, masking, removing material priorto and/or following leaching) may be utilized to form various boundaryregion 635 profiles.

FIGS. 15A-17 show exemplary superabrasive elements 10 coated withmasking layers. According to various embodiments, portions ofsuperabrasive element 10 may be coated or otherwise covered with one ormore masking layers that prevent and/or delay a leaching agent fromcontacting selected regions of superabrasive element 10 during leaching.For example, a first masking layer 752 and a second masking layer 754may be formed on or disposed abutting at least a portion ofsuperabrasive element 10.

As shown in FIGS. 15A-16 , first masking layer 752 may be disposed on atleast a portion of superabrasive face 20, such as a central portion ofsuperabrasive face 20 surrounding central axis 28. Second masking layer754 may be disposed on at least a portion of peripheral surface 15 andrear surface 18 of superabrasive element 10 so as to surround at least aportion of superabrasive table 14 and/or substrate 12. First maskinglayer 752 and second masking layer 754 may prevent damage to selectedportions of superabrasive element 10 and may provide a desired leachprofile when superabrasive element 10 is exposed to various leachingagents. For example, first masking layer 752 and/or second masking layer754 may prevent or delay a leaching solution from contacting certainportions of superabrasive element 10, such as portions of substrate 12,portions of superabrasive table 14, or both, during leaching.

In various examples, first masking layer 752 and/or second masking layer754 may comprise one or more materials that are substantially inertand/or otherwise resistant and/or impermeable to acids, bases, and/orother reactive compounds present in a leaching solution used to leachsuperabrasive element 10. Optionally, first masking layer 752 and/orsecond masking layer 754 may comprise a material that breaks down in thepresence of a leaching agent, such as a material that is at leastpartially degraded (e.g., at least partially dissolved) at a selectedrate during exposure to the leaching agent.

In some embodiments, first masking layer 752 and second masking layer754 may comprise one or more materials exhibiting significant stabilityduring exposure to a leaching agent. According to various embodiments,first masking layer 752 and second masking layer 754 may comprise anysuitable material, including metals, alloys, polymers, carbonallotropes, oxides, carbides, glass materials, ceramics, composites,membrane materials (e.g. permeable or semi-permeable materials), and/orany combination of the foregoing, without limitation. First maskinglayer 752 and second masking layer 754 may be affixed to superabrasiveelement 10 through any suitable mechanism, without limitation,including, for example, direct bonding, bonding via an intermediatelayer, such as an adhesive or braze joint, mechanical attachment, suchas mechanical fastening, frictional attachment, and/or interferencefitting. In some embodiments, first masking layer 752 and/or secondmasking layer 754 may comprise a coating or layer of material that isformed on or otherwise adhered to at least a portion of superabrasiveelement 10. In additional embodiments, first masking layer 752 and/orsecond masking layer 754 may comprise a material that is temporarilyfixed to superabrasive element 10. For example, first masking layer 752may comprise a polymer member (e.g., o-ring, gasket, disk) that ismechanically held in place (e.g., by clamping) during exposure to aleaching agent.

First masking layer 752 and second masking layer 754 may be formed overany suitable portions superabrasive element 10. For example, asillustrated in FIGS. 15A and 15B, first masking layer 752 may be formedover a central portion of superabrasive face 20 about central axis 28.First masking layer 752 may be separated from superabrasive chamfer 24.For example, first masking layer 752 may not be directly adjacent toand/or in contact with edge 30 formed at the intersection ofsuperabrasive face 20 and superabrasive chamfer 24. Second masking layer754 may be formed over at least a portion of substrate 12 andsuperabrasive table 14. For example, as shown in FIGS. 15A and 15B,second masking layer 754 may be formed over rear surface 18 andsubstrate side surface 16 of substrate 12 so as to substantiallysurround substrate 12. Additionally, second masking layer 754 may beformed over a portion of superabrasive side surface 22. In someembodiments, second masking layer 754 may also be separated fromsuperabrasive chamfer 24. For example, second masking layer 754 may notbe directly adjacent to and/or in contact with edge 31 formed at theintersection of superabrasive side surface 22 and superabrasive chamfer24.

FIGS. 15C and 15D illustrate masking layers formed over portions of asuperabrasive element 10 having an edge 25 formed at the intersection ofsuperabrasive face 20 and superabrasive side surface 22. As illustrated,for example, in FIGS. 15C and 15D, first masking layer 752 may be formedover a central portion of superabrasive face 20 about central axis 28.First masking layer 752 may not be directly adjacent to and/or incontact with edge 25. In additional embodiments, first masking layer 752may be formed adjacent to and/or in contact with edge 25. Second maskinglayer 754 may be formed over at least a portion of substrate 12 andsuperabrasive table 14. For example, as shown in FIGS. 15C and 15D,second masking layer 754 may be formed over rear surface 18 andsubstrate side surface 16 of substrate 12 so as to substantiallysurround substrate 12. Additionally, second masking layer 754 may beformed over a portion of superabrasive side surface 22. In someembodiments, second masking layer 754 may not be directly adjacent toand/or in contact with edge 25, as shown in FIG. 15C. In additionalembodiments, second masking layer 754 may be disposed adjacent to and/orin contact with edge 25, as shown in FIG. 15D.

According to some embodiments, first masking layer 752 and/or secondmasking layer 754 may be disposed adjacent to and/or in contact with atleast a portion of superabrasive chamfer 24. For example, as illustratedin FIG. 16 , first masking layer 752 may substantially coversuperabrasive face 20 such that first masking layer 752 is formedadjacent to edge 30 of superabrasive table 14. Additionally, secondmasking layer 754 may substantially cover superabrasive side surface 22such that second masking layer 754 is formed adjacent to edge 31 ofsuperabrasive table 14. In some embodiments, first masking layer 752and/or second masking layer 754 may be formed over at least a portionsuperabrasive chamfer 24.

The configuration illustrated in FIGS. 15A-16 may enable selectiveleaching of portions of superabrasive element 10 to form a desired leachprofile within superabrasive table 14. For example, a volume ofsuperabrasive table 14 adjacent to an uncovered region between firstmasking layer 752 and second masking layer 754 may be leached to agreater depth than surrounding portions of superabrasive table 14covered by first masking layer 752 and second masking layer 754. Theconfigurations illustrated in FIGS. 15A-16 may result in the formationof leached volumes in portions of superabrasive table 14 located nearsuperabrasive chamfer 24 during leaching.

Following exposure to a leaching solution, first masking layer 752and/or second masking layer 754 may be substantially removed fromsuperabrasive table 14 and/or substrate 12 using any suitable technique,including, for example, lapping, grinding, and/or removal using suitablechemical agents. According to certain embodiments, first masking layer752 and/or second masking layer 754 may be peeled, cut, ground, lapped,and/or otherwise physically or chemically removed from superabrasiveelement 10. In some embodiments, following or during removal of firstmasking layer 752 and/or second masking layer 754, one or more surfacesof superabrasive table 14 and/or substrate 12 may be processed to form adesired surface texture and/or finish using any suitable technique,including, for example, lapping, grinding, and/or otherwise physicallyand/or chemically treating the one or more surfaces.

FIG. 17 is a cross-sectional side view of an exemplary superabrasiveelement 10 coated with masking layers according to at least oneembodiment. As shown in FIG. 17 , superabrasive element 10 may be coatedwith various masking layers that prevent and/or delay a leaching agentfrom contacting selected regions of superabrasive element 10 duringleaching. According to some embodiments, a first protective maskinglayer 852 and a second protective masking layer 854 may be formed on atleast a portion of superabrasive element 10. Additionally, a first atleast partially degrading masking layer 856 and a second at leastpartially degrading masking layer 858 may be formed on at least aportion of superabrasive element 10.

As shown in FIG. 17 , first protective masking layer 852 may be formedon at least a portion of superabrasive face 20, such as a centralportion of superabrasive face 20 surrounding central axis 28. Secondprotective masking layer 854 may be formed on at least a portion ofperipheral surface 15 and rear surface 18 of superabrasive element 10 soas to surround at least a portion of superabrasive table 14 and/orsubstrate 12. First protective masking layer 852 and second protectivemasking layer 854 may prevent damage to selected portions ofsuperabrasive element 10 and may provide a desired leach profile whensuperabrasive element 10 is exposed to various reactive agents. Forexample, first protective masking layer 852 and/or second protectivemasking layer 854 may prevent or delay a leaching solution fromcontacting certain portions of superabrasive element 10, such asportions of substrate 12, portions of superabrasive table 14, or both,during leaching. In various examples, first protective masking layer 852and/or second protective masking layer 854 may comprise one or morematerials that are substantially inert and/or otherwise resistant and/orimpermeable to acids, bases, and/or other reactive compounds present ina leaching solution used to leach superabrasive element 10.

First degrading masking layer 856 may be formed on at least a portion ofsuperabrasive element 10 adjacent to first protective masking layer 852.For example, first degrading masking layer 856 may be formed on portionsof superabrasive face 20 and/or superabrasive chamfer 24. Seconddegrading masking layer 858 may be formed on at least a portion ofsuperabrasive element 10 adjacent to second protective masking layer854. For example, second degrading masking layer 858 may be formed onportions of superabrasive side surface 22 and/or superabrasive chamfer24. As shown in FIG. 17 , first degrading masking layer 856 may beseparated from second degrading masking layer 858. For example, a spacebetween first degrading masking layer 856 and second degrading maskinglayer 858 may be formed over at least a portion of superabrasive table14, such as, for example, at least a portion of superabrasive chamfer24. Optionally, a space between first degrading masking layer 856 andsecond degrading masking layer 858 may also be formed over a portion ofsuperabrasive face 20 and/or superabrasive side surface 22.

According to at least one embodiment, first degrading masking layer 856and/or second degrading masking layer 858 may comprise a material thatbreaks down in the presence of a leaching agent. First degrading maskinglayer 856 and/or second degrading masking layer 858 may comprise, forexample, a polymeric material that breaks down at a desired rate duringexposure to the leaching agent. As first degrading masking layer 856 andsecond degrading masking layer 858 disintegrate during leaching,portions of superabrasive element 10 that were covered by firstdegrading masking layer 856 and second degrading masking layer 858 maybecome exposed to the leaching agent. According to additionalembodiments, first degrading masking layer 856 and/or second degradingmasking layer 858 may comprise a material that is more permeable to aleaching agent than first protective masking layer 852 and/or secondprotective masking layer 854. In at least one embodiment, firstdegrading masking layer 856 and/or second degrading masking layer 858may be not substantially degrade when exposed to a leaching agent butmay be semi-permeable or permeable to the leaching agent.

First protective masking layer 852, second protective masking layer 854,first degrading masking layer 856, and second degrading masking layer858 may each comprise any suitable material, including metals, alloys,polymers, carbon allotropes, oxides, carbides, glass materials,ceramics, composites, membrane materials (e.g. permeable orsemi-permeable materials), and/or any combination of the foregoing,without limitation. Additionally, first protective masking layer 852,second protective masking layer 854, first degrading masking layer 856,and second degrading masking layer 858 may be affixed to superabrasiveelement 10 through any suitable mechanism, without limitation,including, for example, direct bonding, bonding via an intermediatelayer, such as an adhesive or braze joint, mechanical attachment, suchas mechanical fastening, frictional attachment, and/or interferencefitting.

The configuration illustrated in FIG. 17 may enable selective leachingof portions of superabrasive element 10 to form a desired leach profilewithin superabrasive table 14. For example, a volume of superabrasivetable 14 adjacent to an uncovered region between first degrading maskinglayer 856 and second degrading masking layer 858 may be leached to agreater depth than surrounding portions of superabrasive table 14. Asfirst degrading masking layer 856 and second degrading masking layer 858are degraded during leaching, portions of superabrasive table 14 thatwere covered by first degrading masking layer 856 and second degradingmasking layer 858 may subsequently be exposed to the leaching agent.Accordingly, volumes of superabrasive table 14 adjacent to the regionspreviously covered by first degrading masking layer 856 and seconddegrading masking layer 858 may be exposed to the leaching agent upondegradation of first degrading masking layer 856 and second degradingmasking layer 858.

Accordingly, the regions of superabrasive table 14 that were originallyadjacent to first degrading masking layer 856 and second degradingmasking layer 858 may have a shallower leach depth than regions ofsuperabrasive table 14 that were adjacent to the uncovered regionbetween first degrading masking layer 856 and second degrading maskinglayer 858. For example, the configuration illustrated in FIG. 17 mayresult in a leach profile having a maximum leach depth in the volume ofsuperabrasive table 14 adjacent to a central portion of superabrasivechamfer 24.

FIG. 18 is a cross-sectional side view of an exemplary superabrasiveelement 10 coated with a masking layer and positioned within a leachingcup 960 according to at least one embodiment. As illustrated in FIG. 18, a masking layer 952 may be formed on or disposed adjacent to at leasta portion of superabrasive face 20, such as a central portion ofsuperabrasive face 20 surrounding central axis 28. According to at leastone embodiment, masking layer 952 may comprise one or more materialsthat are substantially inert and/or otherwise resistant and/orimpermeable to acids, bases, and/or other reactive compounds present ina leaching solution used to leach superabrasive element 10.

Protective leaching cup 960 may comprise a rear wall 962 and a side wall964 defining a cavity 967 extending from opening 966. Protectiveleaching cup 960 may be formed of any suitable material, withoutlimitation. For example, protective leaching cup 960 may comprise aflexible, elastic, malleable, and/or otherwise deformable materialconfigured to surround and/or contact at least a portion ofsuperabrasive element 10. Protective leaching cup 960 may prevent damageto superabrasive element 10 when at least a portion of superabrasiveelement 10 is exposed to various leaching agents. For example,protective leaching cup 960 may prevent a leaching solution fromchemically contacting and/or damaging certain portions of superabrasiveelement 10, such as portions of substrate 12, portions of superabrasivetable 14, or both, during leaching.

In various embodiments, protective leaching cup 960 may comprise one ormore materials that are substantially inert and/or otherwise resistantto acids, bases, and/or other reactive components present in a leachingsolution used to leach superabrasive element 10. In some embodiments,protective leaching cup 960 may comprise one or more materialsexhibiting significant stability at various temperatures and/orpressures, including elevated temperatures and/or pressures used inleaching and/or otherwise processing superabrasive element 10. In someembodiments, protective leaching cup 960 may include one or morepolymeric materials, such as, for example, nylon,polytetrafluoroethylene (PTFE), polyethylene, polypropylene, rubber,silicone, and/or other polymers, and/or a combination of any of theforegoing, without limitation. For example, protective leaching cup 960may comprise PTFE blended with one or more other polymeric materials.Protective leaching cup 960 may be formed using any suitable technique.For example, protective leaching cup 960 may comprise a polymericmaterial that is shaped through a molding process (e.g., injectionmolding, blow molding, compression molding, drawing, etc.) and/or amachining process (e.g., grinding, lapping, milling, boring, etc.).

In at least one embodiment, protective leaching cup 960 may comprise amaterial that is configured to conform to an exterior portion ofsuperabrasive element 10. For example, protective leaching cup 960 mayinclude a malleable and/or elastically deformable material that conformsto an exterior shape of a portion of superabrasive table 14 abuttingprotective leaching cup 960, such as superabrasive side surface 22.According to some embodiments, protective leaching cup 960 may comprisea material, such as a polymeric material (e.g., elastomer, rubber,plastic, etc.), that conforms to surface imperfections of superabrasiveside surface 22 and/or substrate side surface 16. Heat and/or pressuremay be applied to protective leaching cup 960 to cause a portion ofprotective leaching cup 960 abutting superabrasive side surface 22 tomore closely conform to superabrasive side surface 22. Accordingly, aseal between superabrasive side surface 22 and a portion of protectiveleaching cup 960 abutting superabrasive side surface 22 may be improved,thereby inhibiting passage of a leaching agent between superabrasiveelement 10 and protective leaching cup 960.

Protective leaching cup 960 may comprise any suitable size, shape and/orgeometry, without limitation. In at least one embodiment, portions ofprotective leaching cup 960 may have a substantially cylindrical outerperiphery surrounding central axis 28. Rear wall 962 and side wall 964may define a cavity 967 within protective leaching cup 960. Cavity 967may be shaped to surround at least a portion of superabrasive element10. Opening 966 may be defined in a portion of protective leaching cup960 opposite rear wall 962 such that cavity 967 extends between opening966 and rear wall 962. According to various embodiments, protectiveleaching cup 960 may comprise a seal region 968 and an encapsulatingregion 969. Seal region 968 may be adjacent to opening 966 andencapsulating region 969 may extend from seal region 968 and may includerear wall 962. According to some embodiments, a portion of side wall 964in seal region 968 may have an inner diameter that is less than aportion of side wall 964 in encapsulating region 969.

When superabrasive element 10 is positioned within protective leachingcup 960, at least a portion of superabrasive element 10, such assuperabrasive table 14 and/or substrate 12, may be positioned adjacentto and/or contacting a portion of protective leaching cup 960. Forexample, at least a portion of seal region 968 of protective leachingcup 960 may be configured to contact at least a portion of peripheralsurface 15 of superabrasive element 10, forming a seal betweenprotective leaching cup 960 and superabrasive element 10 that ispartially or fully impermeable to various fluids, such as a leachingagent. As shown in FIG. 18 , superabrasive element 10 may be positionedwithin protective leaching cup 960 so that at least a portion of sealregion 968 of protective leaching cup 960 contacts and forms a seal withat least a portion of peripheral surface 15, such as at least a portionof superabrasive side surface 22 and/or at least a portion of substrateside surface 16.

The configuration illustrated in FIG. 18 may enable selective leachingof portions of superabrasive element 10 to form a desired leach profilewithin superabrasive table 14. For example, a volume of superabrasivetable 14 adjacent to an uncovered region between masking layer 952 andseal region 968 of protective leaching cup 960 may be leached to agreater depth than surrounding portions of superabrasive table 14covered by masking layer 952 or seal region 968. Leaching such aconfiguration may result in the formation of leached volumes in portionsof superabrasive table 14 located near superabrasive chamfer 24 duringleaching.

FIGS. 19-27 illustrate superabrasive elements having various leachprofiles according to some embodiments. While the superabrasive elementsshown in FIGS. 19-27 are each illustrated as comprising a superabrasivetable detached from a substrate, a superabrasive element having asuperabrasive table joined to a substrate (see, e.g., FIGS. 1 and 2 )may be configured in the same or similar manner as described herein withreference to FIGS. 19-27 . The configurations illustrated in each ofFIGS. 19-27 may reduce or eliminate undesired spalling, cracking, and/orthermal damage of the illustrated superabrasive elements duringdrilling.

FIG. 19 shows an exemplary superabrasive element 1010 comprising asuperabrasive table 1014 having a rear surface 1018, a superabrasiveface 1020, and a peripheral surface 1015. Superabrasive element 1010 mayalso comprise an edge 1025 (i.e., sloped or angled) and/or any othersuitable surface shape at the intersection of peripheral surface 1015and superabrasive face 1020, including, without limitation, an arcuatesurface (e.g., a radius, an ovoid shape, or any other rounded shape), asharp edge, multiple chamfers/radii, a honed edge, and/or combinationsof the foregoing. Peripheral surface 1015 of superabrasive element 1010may radially surround a central axis 1028 of superabrasive element 1010.

Superabrasive element 1010 may include a first volume 1032 comprising aninterstitial material and a second volume 1034 having a lowerconcentration of the interstitial material than first volume 1032.Portions of superabrasive table 1014, such as second volume 1034, may beleached or otherwise processed to remove interstitial materials, such asa metal-solvent catalyst, from the interstitial regions. A boundaryregion 1035 may extend between first volume 1032 and second volume 1034so as to border at least a portion of first volume 1032 and secondvolume 1034. Boundary region 1035 may include amounts of an interstitialmaterial varying between an amount of the interstitial material in firstvolume 1032 and an amount of the interstitial material in second volume1034. In other embodiments, the boundary may be well defined (i.e.,boundary region 1035 may be thin compared to a depth of second volume1034).

As shown in FIG. 19 , first volume 1032 may extend between rear surface1018 and boundary region 1035. Second volume 1034 may be formed adjacentto a substantial portion of superabrasive face 1020. For example, asshown in FIG. 19 , second volume 1034 may extend along the entirediameter of second volume 1024. Boundary region 1035 bordering secondvolume 1034 may extend in a direction generally parallel tosuperabrasive face 1020. Additionally, a portion of second volume 1034may extend along at least a portion of peripheral surface 1015 so as toradially surround at least a portion of first volume 1032. A portion ofboundary region 1035 may extend in a direction generally parallel toperipheral surface 1015. According to some embodiments, boundary region1035 may have a substantially consistent thickness along peripheralsurface 1015 and/or along superabrasive face 1020.

FIG. 20 shows an exemplary superabrasive element 1110 comprising asuperabrasive table 1114 having a rear surface 1118, a superabrasiveface 1120, and a peripheral surface 1115. Superabrasive element 1110 mayalso comprise an edge 1125 at the intersection of peripheral surface1115 and superabrasive face 1120. Peripheral surface 1115 ofsuperabrasive element 1110 may radially surround a central axis 1128 ofsuperabrasive element 1110.

Superabrasive element 1110 may include a first volume 1132 comprising aninterstitial material and a second volume 1134 having a lowerconcentration of the interstitial material than first volume 1132.Portions of superabrasive table 1114, such as second volume 1134 may beleached or otherwise processed to remove interstitial materials, such asa metal-solvent catalyst, from the interstitial regions. A boundaryregion 1135 may extend between first volume 1132 and second volume 1134so as to border at least a portion of first volume 1132 and secondvolume 1134. Boundary region 1135 may include amounts of an interstitialmaterial varying between an amount of the interstitial material in firstvolume 1132 and an amount of the interstitial material in second volume1134.

As shown in FIG. 20 , first volume 1132 may extend between rear surface1118 and boundary region 1135. Second volume 1134 may be formed adjacentto a substantial portion of superabrasive face 1120 and may extendbetween boundary region 1135 and superabrasive face 1120. Boundaryregion 1135 bordering second volume 1134 may extend along an undulating,zig-zag, and/or any/other suitable non-linear profile. Superabrasiveelement 1110 may be leached and/or otherwise processed in any suitablemanner to form second volume 1134.

Superabrasive element 1110 may comprise distinct layers, including amore leachable layer 1170, a less leachable layer 1172, and a compositelayer 1171. More leachable layer 1170 may comprise a superabrasivematerial, such as polycrystalline diamond, that is susceptible toleaching at a faster rate than a superabrasive material forming lessleachable layer 1172. Various factors, such as, for example, diamondgrain size, interstitial materials, processing conditions (temperature,pressure, etc.), and/or porosity may be selected to form each of moreleachable layer 1170 and less leachable layer 1172 having desiredleaching characteristics. Examples of superabrasive elements comprisingmore leachable layers and less leachable layers may be found in U.S.Patent Publication No. 2011/0023375, the disclosure of which isincorporated herein, in its entirety, by this reference. Composite layer1171 may comprise both portions of the superabrasive material formingmore leachable layer 1170 and portions of the superabrasive materialforming less leachable layer 1172. Such materials forming each of moreleachable layer 1170 and less leachable layer 1172 may be intermixed inany suitable manner in composite layer 1171. For example, as illustratedin FIG. 20 , composite layer 1171 may include an undulating or otherwiseuneven boundary region 1135 extending between the superabrasivematerials forming each of more leachable layer 1170 and less leachablelayer 1172, respectively. Composite layer 1171 may serve to distributeor transfer a stress gradient between the leached and unleached portions(i.e. more leachable layer 1170 and less leachable layer 1172) ofsuperabrasive element 1110.

FIG. 21 illustrates an exemplary superabrasive element 1210 comprising asuperabrasive table 1214 having a rear surface 1218, a superabrasiveface 1220, and a peripheral surface 1215. Superabrasive element 1210 mayalso comprise an edge 1225 at the intersection of peripheral surface1215 and superabrasive face 1220. Peripheral surface 1215 ofsuperabrasive element 1210 may radially surround a central axis 1228 ofsuperabrasive element 1210.

Superabrasive element 1210 may include a first volume 1232 comprising aninterstitial material, a second volume 1233 having a lower concentrationof the interstitial material than first volume 1232, and a third volume1234 having a lower concentration of the interstitial material thansecond volume 1233. Portions of superabrasive table 1214, such as thirdvolume 1234 and second volume 1233 may be leached or otherwise processedto remove interstitial materials, such as a metal-solvent catalyst, fromthe interstitial regions. As shown in FIG. 21 , first volume 1232 may belocated adjacent to rear surface 1218, third volume 1234 may be locatedadjacent to superabrasive face 1220, and second volume 1233 may belocated between first volume 1232 and third volume 1234.

Superabrasive element 1210 may be leached and/or otherwise processed inany suitable manner to form second volume 1233 and third volume 1234.According to at least one embodiment, superabrasive element 1210 may beexposed to a leaching agent for a length of time sufficient tosubstantially leach an interstitial material, such as a metal-solventcatalyst, from both third volume 1234 and second volume 1233.Subsequently, an interstitial material may be introduced into secondvolume 1233 using any suitable technique. For example, followingleaching, superabrasive element 1210 may be heat treated to extrude orotherwise remove at least some of a solvent-metal catalyst and/or othermetals or interstitial materials from first volume 1232 to second volume1233. As the metal-solvent catalyst flows from first volume 1232 intosecond volume 1233, the metal-solvent catalyst may at least partiallyoccupy interstitial spaces within second volume 1233.

Following the heated extrusion of the metal-solvent catalyst into secondvolume 1233, superabrasive element 1210 may be cooled to solidify themetal-solvent catalyst within superabrasive element 1210. Theconcentration of metal-solvent catalyst in second volume 1233 may belower than the metal-solvent catalyst concentration in the unleachedfirst volume 1232 and higher than the metal-solvent catalystconcentration in the leached third volume 1234. Second volume 1233 mayserve as a transition for the stress gradient between the leached andunleached portions (i.e. third volume 1234 and first volume 1232) ofsuperabrasive element 1110, thereby reducing or eliminating undesiredspalling, cracking, and/or thermal damage of the illustratedsuperabrasive elements during drilling.

Generally, combinations of the features, methods, and embodimentsdescribed herein may be utilized to create a desired size and/or shapeof the leached region of a superabrasive element. For example,superabrasive elements may be processed according to any combination offeatures, methods, or embodiments described herein (e.g., leachability,masking, removing material prior to and/or following leaching). In someembodiments, superabrasive a superabrasive element may be leached and/orprocessed according to one or more methods described herein, andsubsequently leached and/or processed at least one additional time toobtain a desired leach profile.

FIG. 22 illustrates an exemplary superabrasive element 610 that isprocessed according to a combination of features, methods, and/orembodiments described herein. Superabrasive element 610 may comprise asuperabrasive table 614 having a rear surface 618, a superabrasive face620, and a peripheral surface 615 (see, e.g., superabrasive element 610illustrated in FIG. 14A). Superabrasive table 614 is bonded to substrate612 along interface 626, which may be a planar or nonplanar interface.Superabrasive element 610 may be formed to include a central recess 647defined in at least a portion of superabrasive table 614. According toat least one example, as shown in FIG. 22 , central recess 647 may bedefined by superabrasive face 620 and a peripheral rim 648 extendingcircumferentially around at least a portion of central recess 647.Peripheral rim 648 may comprise a side surface 650 extending upward fromsuperabrasive face 620.

One or more masking layers (see, e.g., masking layers illustrated inFIGS. 15A-18 ) may be used to cover portions of superabrasive element610 so as to prevent and/or delay a leaching agent from contactingselected regions of superabrasive element 10 during leaching, therebycreating a desired size and/or shape of the leached region ofsuperabrasive table 614. For example, as shown in FIG. 22 , a firstmasking layer 752 and a second masking layer 754 may be formed on ordisposed abutting at least a portion of superabrasive element 610.According to at least one embodiment, first masking layer 752 may bedisposed on at least a portion of superabrasive face 620 within centralrecess 647. Second masking layer 754 may be disposed on at least aportion of peripheral surface 615 and rear surface 618 of superabrasiveelement 610 so as to surround at least a portion of superabrasive table614 and/or substrate 612. For example, as shown in FIG. 22 , secondmasking layer 754 may extend to an upper edge 625 of peripheral rim 648.According to various embodiments, first masking layer 752 and secondmasking layer 754 may be disposed in any other suitable configurationover any other desired regions of superabrasive element 610, withoutlimitation.

Following exposure to a leaching solution, first masking layer 752and/or second masking layer 754 may be substantially removed fromsuperabrasive table 14 and/or substrate 12 using any suitable technique,including, for example, lapping, grinding, and/or removal using suitablechemical agents. According to certain embodiments, first masking layer752 and/or second masking layer 754 may be peeled, cut, ground, lapped,and/or otherwise physically or chemically removed from superabrasiveelement 10. In some embodiments, following or during removal of firstmasking layer 752 and/or second masking layer 754, one or more surfacesof superabrasive table 14 and/or substrate 12 may be processed to form adesired surface texture and/or finish using any suitable technique,including, for example, lapping, grinding, and/or otherwise physicallyand/or chemically treating the one or more surfaces.

According to various embodiments, superabrasive element 610 may befurther processed (either prior to or following removal of first maskinglayer 752 and/or second masking layer 754) using any suitable materialremoval technique, without limitation. For example, portions ofsuperabrasive element 610 may be smoothed and/or polished using anysuitable mechanical, chemical, electrical, and/or laser processingtechnique, including grinding, lapping, milling, polishing, and/or anyother suitable mechanical processing technique. According to at leastone embodiment, peripheral rim 648 may be removed so that superabrasiveface 620 is the top-most portion of superabrasive element 610 and/or achamfer may be formed on a portion of superabrasive table 614 betweensuperabrasive face 620 and superabrasive side surface 622 (see, e.g.,FIGS. 14C-14F).

FIGS. 23A-25 illustrate exemplary superabrasive elements 1310 havingleached volumes formed adjacent to chamfered portions of thesuperabrasive elements 1310. Superabrasive element 1310 may include asubstrate 1312 and a superabrasive table 1314 forming a rear surface1318, a superabrasive face 1320, and a peripheral surface 1315.Superabrasive table 1314 may also form a chamfer 1324 and one or morecutting edges, such as edge 1330 and edge 1331, adjacent to chamfer1324.

Superabrasive table 1314 may include a first volume 1332 comprising aninterstitial material and a second volume 1334 having a lowerconcentration of the interstitial material than first volume 1332.Portions of superabrasive table 1314, such as second volume 1334 may beleached or otherwise processed to remove interstitial materials, such asa metal-solvent catalyst, from the interstitial regions. Second volume1334 may be created during leaching of superabrasive table 1314according to any suitable leaching technique. For example, portions ofsuperabrasive element 1310 may be masked and/or otherwise covered duringat least part of a leaching process to prevent a leaching solution fromcontacting selected portions of superabrasive element 1310 (see, e.g.,FIGS. 15A-18 ). In some embodiments, superabrasive element 1310 mayfirst be leached, after which portions of superabrasive element 1310 maybe removed to modify the shape of first volume 1332 and/or second volume1334 according to one or more methods discussed herein (see, e.g., FIGS.7-14B).

A boundary region 1335 may extend between first volume 1332 and secondvolume 1334. Boundary region 1335 may include amounts of metal-solventcatalyst varying between an amount of metal-solvent catalyst in firstvolume 1332 and an amount of metal-solvent catalyst in second volume1334. As illustrated in FIGS. 23A-25 , first volume 1332 may be locatedadjacent to a central portion of superabrasive face 1320. For example,first volume 1332 may be disposed about central axis 1328. First volume1332 may extend between rear surface 1318 and superabrasive face 1320with first volume 1332 forming at least a portion of superabrasive face1320 such that at least a central portion of superabrasive face 1320located about central axis 1328 is defined by first volume 1332.

Second volume 1334 may be formed adjacent to superabrasive chamfer 1324so as to surround at least a portion of first volume 1332. For example,second volume 1334 may be generally formed in an annular shapesurrounding at least a portion of first volume 1332. First volume 1332,second volume 1334, and boundary region 1335 may be formed to anysuitable size and/or shape within superabrasive table 1314, withoutlimitation. For example, boundary region 1335 may extend along agenerally straight, angular, curved, and/or variable (e.g., zigzag,undulating) profile between first volume 1332 and second volume 1334.

As shown in FIG. 23A, second volume 1334 may be formed adjacent tosuperabrasive chamfer 1324 and superabrasive face 1320, and boundaryregion 1335 may extend from superabrasive face 1320 to edge 1331 formedat the intersection of superabrasive chamfer 1324 and peripheral surface1315, with a portion of boundary region 1335 extending generallyparallel to superabrasive chamfer 1324. According to some embodiments,as shown in FIG. 23B, second volume 1334 may be formed adjacent tosuperabrasive chamfer 1324, superabrasive face 1320, and peripheralsurface 1315, and boundary region 1335 may extend generally parallel tosuperabrasive chamfer 1324 from superabrasive face 1320 to peripheralsurface 1315.

According to various embodiments, as shown in FIG. 24 , second volume1334 may be formed adjacent to superabrasive chamfer 1324, superabrasiveface 1320, and peripheral surface 1315, and boundary region 1335 mayextend from superabrasive face 1320 to peripheral surface 1315, with aportion of boundary region 1335 extending generally parallel tosuperabrasive chamfer 1324 and another portion of boundary region 1335extending generally parallel to peripheral surface 1315.

According to some embodiments, as shown in FIG. 25 , second volume 1334may be formed adjacent to superabrasive chamfer 1324 and peripheralsurface 1315, and boundary region 1335 may extend from edge 1330 formedat the intersection of superabrasive chamfer 1324 and superabrasive face1320 to peripheral surface 1315, with a portion of boundary region 1335extending generally parallel to peripheral surface 1315.

FIGS. 26A and 26B illustrate exemplary superabrasive elements 1410having leached volumes formed adjacent to chamfered portions of thesuperabrasive elements 1410. Superabrasive element 1410 may include asubstrate 1412 and a superabrasive table 1414 forming a rear surface1418, a superabrasive face 1420, and a peripheral surface 1415.Superabrasive table 1414 may also form a chamfer 1424 and one or morecutting edges, such as edge 1430 and edge 1431, adjacent to chamfer1424.

Superabrasive table 1414 may include a first volume 1432 comprising aninterstitial material and a second volume 1434 having a lowerconcentration of the interstitial material than first volume 1432.Portions of superabrasive table 1414, such as second volume 1434 may beleached or otherwise processed to remove interstitial materials, such asa metal-solvent catalyst, from the interstitial regions. Second volume1434 may be created during leaching of superabrasive table 1414according to any suitable leaching technique. For example, portions ofsuperabrasive element 1410 may be masked and/or otherwise covered duringat least part of a leaching process to prevent a leaching solution fromcontacting selected portions of superabrasive element 1410 (see, e.g.,FIGS. 15A-18 ). In some embodiments, superabrasive element 1410 mayfirst be leached, after which portions of superabrasive element 1410 maybe removed to modify the shape of first volume 1432 and/or second volume1434 according to one or more methods discussed herein (see, e.g., FIGS.7-14B).

A boundary region 1435 may extend between first volume 1432 and secondvolume 1434. Boundary region 1435 may include amounts of metal-solventcatalyst varying between an amount of metal-solvent catalyst in firstvolume 1432 and an amount of metal-solvent catalyst in second volume1434. As illustrated in FIGS. 26A and 26B, first volume 1432 may belocated adjacent to a central portion of superabrasive face 1420. Forexample, first volume 1432 may be disposed about central axis 1428.First volume 1432 may extend between rear surface 1418 and superabrasiveface 1420, with first volume 1432 forming substantially all ofsuperabrasive face 1420 such that a central portion of superabrasiveface 1420 located about central axis 1428 is defined by first volume1432. Additionally, first volume 1432 may form substantially all ofperipheral surface 1415.

Second volume 1434 may be formed adjacent to superabrasive chamfer 1424so as to surround at least a portion of first volume 1432. For example,second volume 1434 may be generally formed in an annular shapesurrounding at least a portion of first volume 1432. First volume 1432,second volume 1434, and boundary region 1435 may be formed to anysuitable size and/or shape within superabrasive table 1414, withoutlimitation. For example, boundary region 1435 may extend along agenerally straight, angular, curved, and/or variable (e.g., zigzag,undulating) profile between first volume 1432 and second volume 1434.

As shown in FIGS. 26A and 26B, second volume 1434 may be formed adjacentto superabrasive chamfer 1424 and boundary region 1435 may extend fromedge 1430 to edge 1431, which are each adjacent to superabrasive chamfer1424. Boundary region 1435 may extend along any suitable profile betweenedge 1430 and edge 1431, without limitation. According to someembodiments, boundary region 1435 may comprise an angular profile, asillustrated in FIG. 26A. In additional embodiments, boundary region 1435may comprise an arcuate profile, as illustrated in FIG. 26B. A thicknessor depth of second volume 1434, as measured perpendicular to a surfaceof superabrasive chamfer 1424, may be maximum generally near the centerof superabrasive chamfer 1424.

FIGS. 27A and 27B illustrate exemplary superabrasive elements 1510having leached volumes formed adjacent to chamfered portions of thesuperabrasive elements 1510. Superabrasive element 1510 may include asubstrate 1512 and a superabrasive table 1514 forming a rear surface1518, a superabrasive face 1520, and a peripheral surface 1515.Superabrasive table 1514 may also form a chamfer 1524 and one or morecutting edges, such as edge 1530 and edge 1531, adjacent to chamfer1524.

Superabrasive table 1514 may include a first volume 1532 comprising aninterstitial material and a second volume 1534 having a lowerconcentration of the interstitial material than first volume 1532.Portions of superabrasive table 1514, such as second volume 1534 may beleached or otherwise processed to remove interstitial materials, such asa metal-solvent catalyst, from the interstitial regions. Second volume1534 may be created during leaching of superabrasive table 1514according to any suitable leaching technique. For example, portions ofsuperabrasive element 1510 may be masked and/or otherwise covered duringat least part of a leaching process to prevent a leaching solution fromcontacting selected portions of superabrasive element 1510 (see, e.g.,FIGS. 15A-18 ). In some embodiments, superabrasive element 1510 mayfirst be leached, after which portions of superabrasive element 1510 maybe removed to modify the shape of first volume 1532 and/or second volume1534 according to one or more methods discussed herein (see, e.g., FIGS.7-14B).

A boundary region 1535 may extend between first volume 1532 and secondvolume 1534. Boundary region 1535 may include amounts of metal-solventcatalyst varying between an amount of metal-solvent catalyst in firstvolume 1532 and an amount of metal-solvent catalyst in second volume1534. As illustrated in FIGS. 27A and 27B, first volume 1532 may belocated adjacent to a central portion of superabrasive face 1520. Forexample, first volume 1532 may be disposed about central axis 1528.First volume 1532 may extend between rear surface 1518 and superabrasiveface 1520, with first volume 1532 forming substantially all ofsuperabrasive face 1520 such that a central portion of superabrasiveface 1520 located about central axis 1528 is defined by first volume1532. Additionally, first volume 1532 may form substantially all ofperipheral surface 1515.

Second volume 1534 may be formed adjacent to superabrasive chamfer 1524so as to surround at least a portion of first volume 1532. For example,second volume 1534 may be generally formed in an annular shapesurrounding at least a portion of first volume 1532. First volume 1532,second volume 1534, and boundary region 1535 may be formed to anysuitable size and/or shape within superabrasive table 1514, withoutlimitation. For example, boundary region 1535 may extend along agenerally straight, angular, curved, and/or variable (e.g., zigzag,undulating) profile between first volume 1532 and second volume 1534.

As shown in FIGS. 27A and 27B, second volume 1534 may be formed adjacentto superabrasive chamfer 1524 and boundary region 1535 may extend fromsuperabrasive face 1520 to peripheral surface 1515. Boundary region 1535may extend along any suitable profile between superabrasive face 1520and peripheral surface 1515, without limitation. Boundary region 1535may comprise, for example, a profile that generally slopes betweensuperabrasive face 1520 and peripheral surface 1515. For example,boundary region 1535 may extend from a region of peripheral surface 1515near edge 1531 to a region of superabrasive face 1520 disposed apartfrom edge 1530. According to some embodiments, as shown in FIGS. 27A and27B, the generally annular-shaped second volume 1534 may comprise agenerally ring-shaped volume that is not perfectly symmetric but isirregular in one or more dimensions. For example, second volume 1534 mayvary in leach depth and/or profile shape, as defined by boundary region1535, at different peripheral regions about central axis 1528.

FIGS. 28-31 illustrate exemplary superabrasive elements 1610 during andfollowing drilling of a formation 1674. Superabrasive elements 1610 usedas cutting elements may be oriented on a drill bit so as to preventspalling and/or other wear or damage to the superabrasive elements 1610.For example, a superabrasive element 1610 having a first volume 1632comprising an interstitial material and a second volume 1634 having alower concentration of the interstitial material than first volume 1632,may be mounted on a drill bit such that the orientation of superabrasiveelement 1610 relative to formation 1674 results in a desired wearpattern during drilling. Such a wear pattern may result in reducedspalling and/or increased superabrasive element life.

As illustrated in FIG. 28 , a superabrasive element 1610 used as acutting element may be mounted to a drill bit (e.g., drill bit 80illustrated in FIG. 32 ) at a back rake angle θ₁ (i.e., the anglebetween superabrasive face 1620 and a line perpendicular to formation1674). With superabrasive element 1610 mounted at back rake angle θ₁, aportion of superabrasive face 1620 and superabrasive chamfer 1624 maycontact and cut through a layer of formation 1674, such as asubterranean formation, during a drilling operation. Over time, assuperabrasive element 1610 is used for drilling formations, at least aportion of superabrasive element 1610 may become worn through use.

FIG. 29 shows superabrasive element 1610 following a period of usedrilling through materials, such as formation 1674 illustrated in FIG.28 . Following extended amounts of drilling, a portion of superabrasiveelement 1610 may become worn down through direct contact with formation1674, thereby forming a wear scar 1676 on superabrasive element 1610.Even after drilling for a significant period of time, wear scar 1676 maynot intersect with boundary region 1635 or first volume 1632. Mountingsuperabrasive element 1610 at back rake angle θ₁ may extend the usablelife of superabrasive element 1610 and/or may prevent spalling ofsuperabrasive element 1610 by delaying or altogether preventing wearscar 1676 from intersecting boundary region 1635 during the usable lifeof a drill bit comprising superabrasive element 1610.

In comparison, as illustrated in FIGS. 30 and 31 , a superabrasiveelement 1610 may be mounted to a drill bit at a back rake angle θ₂(i.e., the angle between superabrasive face 1620 and a lineperpendicular to formation 1674). Back rake angle θ₂ is smaller thanback rake angle θ₁ illustrated in FIGS. 28 and 29 . As shown in FIG. 31, a portion of superabrasive element 1610 may become worn down throughdirect contact with formation 1674 to form a wear scar 1677 onsuperabrasive element 1610. In comparison to wear scar 1676 illustratedin FIG. 29 , wear scar 1677 illustrated in FIG. 31 may intersect withboundary region 1635 and first volume 1632 following an equivalentamount of drilling under the same conditions and for the same period oftime as superabrasive element 1610 shown in FIG. 29 . The intersectionof wear scar 1677 with boundary region 1635 and first volume 1632, asillustrated in FIG. 31 , may lead to increased spalling and/or otherundesirable wear in comparison with the configuration and orientation ofsuperabrasive element 1610 illustrated in FIGS. 28 and 29 . Accordingly,mounting superabrasive element 1610 to a drill bit at a back rake angleθ₁ that is larger than back rake θ₂ may result in reduced spallingand/or other wear and increased usable life of superabrasive element1610.

FIG. 32 is a perspective view of an exemplary drill bit 80 according toat least one embodiment. Drill bit 80 may represent any type or form ofearth-boring or drilling tool, including, for example, a rotary drillbit. As illustrated in FIG. 32 , drill bit 80 may comprise a bit body 81having a longitudinal axis 84. Bit body 81 may define a leading endstructure for drilling into a subterranean formation by rotating bitbody 81 about longitudinal axis 84 and applying weight to bit body 81.Bit body 81 may include radially and longitudinally extending blades 79with leading faces 82 and a threaded pin connection 83 for connectingbit body 81 to a drill string.

At least one superabrasive element 10 and/or at least one superabrasiveelement 310 may be coupled to bit body 81. For example, as shown in FIG.32 , a plurality of superabrasive elements 10 may be coupled to blades79. Drill bit 80 may utilize any of the disclosed superabrasive elements10 as cutting elements. Circumferentially adjacent blades 79 may defineso-called junk slots 85 therebetween. Junk slots 85 may be configured tochannel debris, such as rock or formation cuttings, away fromsuperabrasive elements 10 during drilling. Drill bit 80 may also includea plurality of nozzle cavities 86 for communicating drilling fluid fromthe interior of drill bit 80 to superabrasive elements 10.

FIG. 32 depicts an example of a drill bit 80 that employs at least onecutting element 10. Drill bit 80 may additionally represent any numberof earth-boring tools or drilling tools, including, for example, corebits, roller-cone bits, fixed-cutter bits, eccentric bits, bicenterbits, reamers, reamer wings, and/or any other downhole tools comprisingsuperabrasive cutting elements and/or discs, without limitation.Superabrasive elements 10 disclosed herein may also be utilized inapplications other than cutting technology. For example, embodiments ofsuperabrasive elements 10 disclosed herein may also form all or part ofheat sinks, wire dies, bearing elements, cutting elements, cuttinginserts (e.g., on a roller cone type drill bit), machining inserts, orany other article of manufacture, as known in the art. According to someexamples, superabrasive elements 10, as disclosed herein, may beemployed in medical device applications, including, without limitation,hip joints, back joints, or any other suitable medical joints. Thus,superabrasive elements 10, as disclosed herein, may be employed in anysuitable article of manufacture. Other examples of articles ofmanufacture that may incorporate superabrasive elements as disclosedherein may be found in U.S. Pat. Nos. 4,811,801; 4,268,276; 4,468,138;4,738,322; 4,913,247; 5,016,718; 5,092,687; 5,120,327; 5,135,061;5,154,245; 5,460,233; 5,544,713; and 6,793,681, the disclosure of eachof which is incorporated herein, in its entirety, by this reference.

In additional embodiments, a rotor and a stator, such as a rotor and astator used in a thrust bearing apparatus, may each include at least onesuperabrasive element according to the embodiments disclosed herein. Byway of example, U.S. Pat. Nos. 4,410,054; 4,560,014; 5,364,192;5,368,398; and 5,480,233, the disclosure of each of which isincorporated herein, in its entirety, by this reference, disclosesubterranean drilling systems that include bearing apparatuses utilizingsuperabrasive elements 10 as disclosed herein.

FIG. 33 is partial cross-sectional perspective view of an exemplarythrust-bearing apparatus 87 according to at least one embodiment.Thrust-bearing apparatus 87 may utilize any of the disclosedsuperabrasive elements 10 and/or superabrasive elements 310 as bearingelements. Thrust-bearing apparatus 87 may also include bearingassemblies 88A and 88B. Each of bearing assembly 88A and 88B may includea support ring 89 fabricated from a material, such as steel, stainlesssteel, or any other suitable material, without limitation.

Each support ring 89 may include a plurality of recesses 90 configuredto receive corresponding superabrasive elements 10. Each superabrasiveelement 10 may be mounted to a corresponding support ring 89 within acorresponding recess 90 by brazing, welding, press-fitting, usingfasteners, or any another suitable mounting technique, withoutlimitation. In at least one embodiment, one or more of superabrasiveelements 10 may be configured according to any of the superabrasiveelement embodiments described herein. For example, each superabrasiveelement 10 may include a substrate 12 and a superabrasive table 14comprising a PCD material. Each superabrasive table 14 may form asuperabrasive face 20 that is utilized as a bearing surface.

Superabrasive faces 20 of bearing assembly 88A may bear against opposingsuperabrasive faces 20 of bearing assembly 88B in thrust-bearingapparatus 87, as illustrated in FIG. 33 . For example, bearing assembly88A of thrust-bearing apparatus 87 may be termed a “rotor.” The rotormay be operably coupled to a rotational shaft. Bearing assembly 88B ofthrust-bearing apparatus 87 may be held substantially stationaryrelative to the bearing assembly 88A and may be termed a “stator.”

FIG. 34 is a perspective view of a radial bearing apparatus 91 accordingto another embodiment. Radial bearing apparatus 91 may utilize any ofthe disclosed superabrasive element embodiments as bearing elements 10Aand 10B. Radial bearing apparatus 91 may include an inner race 92Apositioned generally within an outer race 92B. Inner race 92A mayinclude a plurality of bearing elements 10A affixed thereto, and outerrace 92B may include a plurality of corresponding bearing elements 10Baffixed thereto. One or more of bearing elements 10A and 10B may beconfigured in accordance with any of the superabrasive elementembodiments disclosed herein.

Inner race 92A may be positioned generally within outer race 92B. Thus,inner race 92A and outer race 92B may be configured such that bearingsurfaces 20A defined by bearing elements 10A and bearing surfaces 20Bdefined by bearing elements 10B may at least partially contact oneanother and move relative to one another as inner race 92A and outerrace 92B rotate relative to each other. According to variousembodiments, thrust-bearing apparatus 87 and/or radial bearing apparatus91 may be incorporated into a subterranean drilling system.

FIG. 35 is a partial cross-sectional perspective view of an exemplarysubterranean drilling system 93 that includes a thrust-bearing apparatus87, as shown in FIG. 33 , according to at least one embodiment. Thesubterranean drilling system 93 may include a housing 94 enclosing adownhole drilling motor 95 (i.e., a motor, turbine, or any othersuitable device capable of rotating an output shaft, without limitation)that is operably connected to an output shaft 96.

The thrust-bearing apparatus 87 shown in FIG. 33 may be operably coupledto downhole drilling motor 95. A rotary drill bit 97, such as a rotarydrill bit configured to engage a subterranean formation and drill aborehole, may be connected to output shaft 96. As illustrated in FIG. 35, rotary drill bit 97 may be a roller cone bit comprising a plurality ofroller cones 98. According to additional embodiments, rotary drill bit97 may comprise any suitable type of rotary drill bit, such as, forexample, a so-called fixed-cutter drill bit. As a borehole is drilledusing rotary drill bit 97, pipe sections may be connected tosubterranean drilling system 93 to form a drill string capable ofprogressively drilling the borehole to a greater depth within asubterranean formation.

A thrust-bearing assembly 88A in thrust-bearing apparatus 87 may beconfigured as a rotor that is attached to output shaft 96 and athrust-bearing assembly 88B in thrust-bearing apparatus 87 may beconfigured as a stator. During a drilling operation using subterraneandrilling system 93, the rotor may rotate in conjunction with outputshaft 96 and the stator may remain substantially stationary relative tothe rotor.

According to various embodiments, drilling fluid may be circulatedthrough downhole drilling motor 95 to generate torque and effectrotation of output shaft 96 and rotary drill bit 97 attached thereto sothat a borehole may be drilled. A portion of the drilling fluid may alsobe used to lubricate opposing bearing surfaces of superabrasive elements10 on thrust-bearing assemblies 88A and 88B.

FIG. 36 illustrates an exemplary method 1700 for processing apolycrystalline diamond element according to at least one embodiment. Asshown in FIG. 36 , a masking layer may be formed over at least a portionof a polycrystalline diamond element (process 1702). In someembodiments, for example, a first masking layer 752 and/or a secondmasking layer 754 may be formed on at least a portion of a superabrasiveelement 10, as illustrated in FIGS. 15A-16 . Superabrasive element 10may comprise an element face (i.e., superabrasive face 20) and aperipheral surface 15 extending around an outer periphery ofsuperabrasive face 20. According to some embodiments, the masking layermay be formed over at least a central portion of superabrasive face 20.

In at least one embodiment, the masking layer may include a firstmasking portion and second masking portion formed over a separateportion of the polycrystalline diamond element than the first maskingportion. For example, as illustrated in FIG. 17 , first and seconddegrading masking layers 856 and 858 may be formed over separateportions of superabrasive element 10 than first protective masking layer852 and second protective masking layer 854.

The polycrystalline diamond element may be exposed to a leachingsolution such that the leaching solution contacts at least a portion ofthe masking layer (process 1704). For example, superabrasive element 10and first masking layer 752 and/or a second masking layer 754, as shownin FIGS. 15A-16 , may be exposed to a leaching solution in any suitablemanner. According to various embodiments, superabrasive element 10 andfirst masking layer 752 and/or a second masking layer 754 may be atleast partially submerged in a leaching agent that is suitable forleaching interstitial materials from exposed portions of superabrasivetable 14. In at least one embodiment, a corrosive leaching agent may beused to remove a metal-solvent catalyst from interstitial spaces betweendiamond grains in superabrasive table 14 of element 10.

FIG. 37 illustrates an exemplary method 1800 for processing apolycrystalline diamond element according to at least one embodiment. Asshown in FIG. 37 , a concave region may be formed in a polycrystallinediamond element (process 1802). For example, a peripheral recess 442 maybe formed in a polycrystalline diamond element 410 at an intersection ofperipheral surface 415 and superabrasive face 420, as shown in FIGS. 7-9.

At least a portion of the concave region may be exposed to a leachingsolution (process 1804). For example, a region of superabrasive element410 that includes peripheral recess 442, as shown in FIGS. 7-9 , may beexposed to a corrosive leaching agent to remove a metal-solvent catalystfrom interstitial spaces between diamond grains in superabrasive table414 of element 410.

At least a portion of the polycrystalline diamond material that wasexposed to the leaching solution may be removed from the polycrystallinediamond element (process 1806). For example, superabrasive element 410may be smoothed and/or polished using any suitable mechanical, chemical,electrical, and/or laser processing technique to remove portions ofexterior polycrystalline diamond material, as illustrated in FIGS. 10and 11 .

The preceding description has been provided to enable others skilled inthe art to best utilize various aspects of the exemplary embodimentsdescribed herein. This exemplary description is not intended to beexhaustive or to be limited to any precise form disclosed. Manymodifications and variations are possible without departing from thespirit and scope of the instant disclosure. It is desired that theembodiments described herein be considered in all respects illustrativeand not restrictive and that reference be made to the appended claimsand their equivalents for determining the scope of the instantdisclosure.

Unless otherwise noted, the terms “a” or “an,” as used in thespecification and claims, are to be construed as meaning “at least oneof” In addition, for ease of use, the words “including” and “having,” asused in the specification and claims, are interchangeable with and havethe same meaning as the word “comprising.”

What is claimed is:
 1. A method of processing a polycrystalline diamondelement, comprising: laser ablating at least a portion of apolycrystalline diamond element to form a laser-shaped nonplanarsurface; exposing at least a portion of the laser-shaped nonplanarsurface to a leaching solution to define a leached volume of thepolycrystalline diamond element and an unleached polycrystalline of thepolycrystalline diamond element; and removing at least a portion of theleached volume of the polycrystalline diamond element from thepolycrystalline diamond element.
 2. The method of claim 1, wherein laserablating the at least a portion of the polycrystalline diamond elementcomprises removing a portion of a peripheral rim extending from acutting face of the polycrystalline diamond element.
 3. The method ofclaim 1, wherein laser ablating the at least a portion of thepolycrystalline diamond element comprises defining a peripheral recessin the polycrystalline diamond element.
 4. The method of claim 1,further comprising shaping the laser-shaped nonplanar surface to definea central recess in a cutting face of the polycrystalline diamondelement.
 5. The method of claim 1, further comprising, prior to thelaser ablating, sintering a diamond particle volume to form thepolycrystalline diamond element.
 6. The method of claim 5, furthercomprising defining a central recess in a cutting face of thepolycrystalline diamond element during the sintering of the diamondparticle volume.
 7. The method of claim 5, further comprising defining aperipheral rim extending from a cutting face of the polycrystallinediamond element during the sintering of the diamond particle volume. 8.The method of claim 7, further comprising leaving a portion of theperipheral rim after laser ablating the at least a portion of thepolycrystalline diamond element.
 9. The method of claim 1, wherein laserablating the at least a portion of the polycrystalline diamond elementcomprises removing material from at least a region adjacent to aperipheral surface of the polycrystalline diamond element.
 10. Themethod of claim 1, wherein removing the at least a portion of theleached volume comprises grinding at least a portion of the leachedvolume.
 11. A method of processing a superabrasive element, comprising:sintering a diamond particle volume to form a superabrasive element;laser ablating at least a portion of the superabrasive element to form alaser-shaped surface having an at least partially nonplanar section; andexposing at least a portion of the laser-shaped surface to a leachingsolution to define a leached volume of the superabrasive element. 12.The method of claim 11, further comprising removing at least a portionof the leached volume of the superabrasive element from thesuperabrasive element.
 13. The method of claim 12, wherein removing theat least a portion of the leached volume comprises grinding at least aportion of the leached volume.
 14. The method of claim 11, furthercomprising forming a peripheral rim extending from a face of thesuperabrasive element during the sintering of the diamond particlevolume.
 15. The method of claim 14, further comprising removing aportion of the peripheral rim extending from the face of thesuperabrasive element during the laser ablating of the at least aportion of the superabrasive element.
 16. The method of claim 11,further comprising forming at least a portion of a peripheral rimextending from a face of the superabrasive element during the laserablating of the superabrasive element.
 17. The method of claim 16,further comprising forming a central recess in a face of thesuperabrasive element during at least one of the sintering of thediamond particle volume or the laser ablating of the superabrasiveelement.
 18. A method of processing a polycrystalline diamond element,comprising: sintering a diamond particle volume to form apolycrystalline diamond element; forming a peripheral rim extending froma face of the polycrystalline diamond element during the sintering ofthe diamond particle volume; laser ablating at least a portion of thepolycrystalline diamond element to form a laser-shaped surface; andexposing at least a portion of the laser-shaped surface to a leachingsolution to define a leached volume of the polycrystalline diamondelement and an unleached volume of the polycrystalline diamond element.19. The method of claim 18, further comprising removing at least aportion of the leached volume of the polycrystalline diamond elementthat was exposed to the leaching solution from the polycrystallinediamond element.
 20. The method of claim 18, further comprising removinga portion of the peripheral rim extending from the face of thepolycrystalline diamond element during the laser ablating of the atleast a portion of the polycrystalline diamond element.